diff --git a/libraries/blocks/README.md b/libraries/blocks/README.md
new file mode 100644
index 00000000..d50704aa
--- /dev/null
+++ b/libraries/blocks/README.md
@@ -0,0 +1,41 @@
+# Blocks API
+
+The Blocks API provides events and utilities for registering and working with blocks.
+
+## Registering Custom Blocks
+
+Block registration should be done in a listener to the `REGISTER_BLOCKS` event. The `BlockRegistry` class provides utility methods for registering blocks.
+
+An example is shown below.
+
+```java
+package com.example;
+
+import net.ornithemc.osl.blocks.api.BlockEvents;
+import net.ornithemc.osl.entrypoints.api.ModInitializer;
+
+public class ExampleInitializer implements ModInitializer {
+
+	@Override
+	public void init() {
+		BlockEvents.REGISTER_BLOCKS.register(ExampleBlocks::init);
+	}
+}
+```
+
+```java
+package com.example;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.api.BlockRegistry;
+import net.ornithemc.osl.core.util.NamespacedIdentifiers;
+
+public final class ExampleBlocks {
+
+	public static final CookieBlock COOKIE = BlockRegistry.register(NamespacedIdentifiers.from("example", "cookie"), new CookieBlock());
+
+	public static void init() {
+	}
+}
+```
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/build.gradle b/libraries/blocks/blocks-mc13w36a-mc14w26c/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/gradle.properties b/libraries/blocks/blocks-mc13w36a-mc14w26c/gradle.properties
new file mode 100644
index 00000000..1cad83f5
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/gradle.properties
@@ -0,0 +1,8 @@
+min_mc_version = 13w36a
+max_mc_version = 14w26c
+minecraft_dependency = >=1.7-alpha.13.36.a <=1.8-alpha.14.26.c
+
+minecraft_version = 1.7.2
+raven_build = 1
+sparrow_build = 1
+nests_build = 3
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java
new file mode 100644
index 00000000..c2d7af63
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.blocks.api;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the blocks lifecycle.
+ */
+public final class BlockEvents {
+
+	/**
+	 * This event is invoked upon game start-up, after Vanilla block registration is finished.
+	 * 
+	 * <p>
+	 * Custom block registration should be done in a listener of this event.
+	 * Helper methods for registering blocks can be found in the {@linkplain
+	 * BlockRegistry} class.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * BlockEvents.REGISTER_BLOCKS.register(() -> {
+	 * 	BlockRegistry.register(99, NamespacedIdentifiers.from("example", "cookie"), new CookieBlock());
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see BlockRegistry
+	 */
+	public static final Event<Runnable> REGISTER_BLOCKS = Event.runnable();
+
+}
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java
new file mode 100644
index 00000000..003e6ec5
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java
@@ -0,0 +1,60 @@
+package net.ornithemc.osl.blocks.api;
+
+import java.util.Set;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.impl.BlockRegistryImpl;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+
+/**
+ * Public access to the Blocks registry.
+ */
+public final class BlockRegistry {
+
+	/**
+	 * @return the numerical ID assigned to the given block.
+	 */
+	public static int getId(Block block) {
+		return BlockRegistryImpl.getId(block);
+	}
+
+	/**
+	 * @return the namespaced ID assigned to the given block.
+	 */
+	public static NamespacedIdentifier getKey(Block block) {
+		return BlockRegistryImpl.getKey(block);
+	}
+
+	/**
+	 * @return the block mapped to the given numerical ID.
+	 */
+	public static Block getBlock(int id) {
+		return BlockRegistryImpl.getBlock(id);
+	}
+
+	/**
+	 * @return the block mapped to the given namespaced ID.
+	 */
+	public static Block getBlock(NamespacedIdentifier key) {
+		return BlockRegistryImpl.getBlock(key);
+	}
+
+	/**
+	 * @return a set containing all namespaced IDs in the registry.
+	 */
+	public static Set<NamespacedIdentifier> keySet() {
+		return BlockRegistryImpl.keySet();
+	}
+
+	/**
+	 * @param <T>   the block type.
+	 * @param id    the numerical ID of the block.
+	 * @param key   the namespaced ID of the block.
+	 * @param block the block to register.
+	 * @return the registered  block.
+	 */
+	public static <T extends Block> T register(int id, NamespacedIdentifier key, T block) {
+		return BlockRegistryImpl.register(id, key, block);
+	}
+}
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/api/block/BlockExtension.java b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/api/block/BlockExtension.java
new file mode 100644
index 00000000..d3cc82ed
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/api/block/BlockExtension.java
@@ -0,0 +1,10 @@
+package net.ornithemc.osl.blocks.api.block;
+
+public interface BlockExtension {
+
+	/**
+	 * @return whether this block is air.
+	 */
+	boolean isAir();
+
+}
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/api/block/BlocksExtension.java b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/api/block/BlocksExtension.java
new file mode 100644
index 00000000..ff20e27f
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/api/block/BlocksExtension.java
@@ -0,0 +1,9 @@
+package net.ornithemc.osl.blocks.api.block;
+
+import net.minecraft.block.Block;
+
+public interface BlocksExtension {
+
+	Block AIR = Block.REGISTRY.get("air");
+
+}
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java
new file mode 100644
index 00000000..d8244fc9
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java
@@ -0,0 +1,72 @@
+package net.ornithemc.osl.blocks.impl;
+
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.api.BlockEvents;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifiers;
+
+public final class BlockRegistryImpl {
+
+	private static boolean locked = true;
+	private static boolean initialized = false;
+
+	public static int getId(Block block) {
+		return Block.REGISTRY.getId(block);
+	}
+
+	public static NamespacedIdentifier getKey(Block block) {
+		String key = Block.REGISTRY.getKey(block);
+		return key == null ? null : NamespacedIdentifiers.parse(key);
+	}
+
+	public static Block getBlock(int id) {
+		return Block.REGISTRY.get(id);
+	}
+
+	public static Block getBlock(NamespacedIdentifier key) {
+		return Block.REGISTRY.get(key.toString());
+	}
+
+	public static Set<NamespacedIdentifier> keySet() {
+		return Block.REGISTRY.keySet().stream().map(NamespacedIdentifiers::parse).collect(Collectors.toSet());
+	}
+
+	public static <T extends Block> T register(int id, NamespacedIdentifier key, T block) {
+		if (locked) {
+			throw new IllegalStateException("register called too " + (initialized ? "late" : "early") + ": registry locked!");
+		} else {
+			Block.REGISTRY.register(id, key.toString(), block);
+		}
+
+		return block;
+	}
+
+	public static void lock() {
+		if (!initialized) {
+			throw new IllegalStateException("cannot lock block registry unless it's been initialized!");
+		}
+
+		locked = true;
+	}
+
+	public static void unlock() {
+		if (initialized) {
+			throw new IllegalStateException("cannot unlock block registry once it's been initialized!");
+		}
+
+		locked = false;
+	}
+
+	public static void init() {
+		if (locked) {
+			throw new IllegalStateException("cannot initialize block registry when it's locked!");
+		}
+
+		BlockEvents.REGISTER_BLOCKS.invoker().run();
+		initialized = true;
+	}
+}
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/BlocksMixinPlugin.java b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/BlocksMixinPlugin.java
new file mode 100644
index 00000000..a242d334
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/BlocksMixinPlugin.java
@@ -0,0 +1,54 @@
+package net.ornithemc.osl.blocks.impl;
+
+import java.util.List;
+import java.util.Set;
+
+import org.objectweb.asm.tree.ClassNode;
+
+import org.spongepowered.asm.mixin.extensibility.IMixinConfigPlugin;
+import org.spongepowered.asm.mixin.extensibility.IMixinInfo;
+
+import net.ornithemc.osl.core.impl.util.MinecraftVersion;
+
+public class BlocksMixinPlugin implements IMixinConfigPlugin {
+
+	public static final boolean AIR_BLOCK_EXISTS = MinecraftVersion.resolve().compareTo("13w38b") >= 0;
+
+	@Override
+	public void onLoad(String mixinPackage) {
+	}
+
+	@Override
+	public String getRefMapperConfig() {
+		return null;
+	}
+
+	@Override
+	public boolean shouldApplyMixin(String targetClassName, String mixinClassName) {
+		if ("net.ornithemc.osl.blocks.impl.mixin.common.AirBlockMixin".equals(mixinClassName)) {
+			return AIR_BLOCK_EXISTS;
+		}
+		if ("net.ornithemc.osl.blocks.impl.mixin.common.BlocksMixin".equals(mixinClassName)) {
+			return !AIR_BLOCK_EXISTS;
+		}
+
+		return true;
+	}
+
+	@Override
+	public void acceptTargets(Set<String> myTargets, Set<String> otherTargets) {
+	}
+
+	@Override
+	public List<String> getMixins() {
+		return null;
+	}
+
+	@Override
+	public void preApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+	}
+
+	@Override
+	public void postApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+	}
+}
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/block/AirBlock.java b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/block/AirBlock.java
new file mode 100644
index 00000000..183b3ac0
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/block/AirBlock.java
@@ -0,0 +1,37 @@
+package net.ornithemc.osl.blocks.impl.block;
+
+import net.minecraft.block.Block;
+import net.minecraft.block.material.Material;
+import net.minecraft.util.math.Box;
+import net.minecraft.world.World;
+
+public class AirBlock extends Block {
+
+	public AirBlock() {
+		super(Material.AIR);
+	}
+
+	@Override
+	public int getRenderType() {
+		return -1;
+	}
+
+	@Override
+	public Box getCollisionShape(World world, int x, int y, int z) {
+		return null;
+	}
+
+	@Override
+	public boolean isSolidRender() {
+		return false;
+	}
+
+	@Override
+	public boolean canRayTrace(int metadata, boolean allowLiquids) {
+		return false;
+	}
+
+	@Override
+	public void dropItems(World world, int x, int y, int z, int metadata, float luck, int fortuneLevel) {
+	}
+}
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/block/BlockExtensionImpl.java b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/block/BlockExtensionImpl.java
new file mode 100644
index 00000000..5f35a77d
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/block/BlockExtensionImpl.java
@@ -0,0 +1,11 @@
+package net.ornithemc.osl.blocks.impl.block;
+
+import net.ornithemc.osl.blocks.api.block.BlockExtension;
+
+public interface BlockExtensionImpl extends BlockExtension {
+
+	@Override
+	default boolean isAir() {
+		throw new AbstractMethodError();
+	}
+}
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/block/BlocksExtensionImpl.java b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/block/BlocksExtensionImpl.java
new file mode 100644
index 00000000..8f2f6e1b
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/block/BlocksExtensionImpl.java
@@ -0,0 +1,6 @@
+package net.ornithemc.osl.blocks.impl.block;
+
+import net.ornithemc.osl.blocks.api.block.BlocksExtension;
+
+public interface BlocksExtensionImpl extends BlocksExtension {
+}
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/AirBlockMixin.java b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/AirBlockMixin.java
new file mode 100644
index 00000000..0fd9972c
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/AirBlockMixin.java
@@ -0,0 +1,16 @@
+package net.ornithemc.osl.blocks.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+
+import net.minecraft.block.AirBlock;
+
+import net.ornithemc.osl.blocks.api.block.BlockExtension;
+
+@Mixin(AirBlock.class)
+public class AirBlockMixin implements BlockExtension {
+
+	@Override
+	public boolean isAir() {
+		return true;
+	}
+}
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java
new file mode 100644
index 00000000..40727408
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java
@@ -0,0 +1,53 @@
+package net.ornithemc.osl.blocks.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.api.block.BlockExtension;
+import net.ornithemc.osl.blocks.impl.BlockRegistryImpl;
+import net.ornithemc.osl.blocks.impl.BlocksMixinPlugin;
+import net.ornithemc.osl.blocks.impl.block.AirBlock;
+
+@Mixin(Block.class)
+public class BlockMixin implements BlockExtension {
+
+	@Inject(
+		method = "init",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private static void osl$blocks$unlockBlockRegistry(CallbackInfo ci) {
+		BlockRegistryImpl.unlock();
+
+		if (!BlocksMixinPlugin.AIR_BLOCK_EXISTS) {
+			Block.REGISTRY.register(0, "air", new AirBlock());
+		}
+	}
+
+	@Inject(
+		method = "init",
+		at = @At(
+			value = "INVOKE",
+			target = "Lnet/minecraft/util/registry/IdRegistry;iterator()Ljava/util/Iterator;"
+		)
+	)
+	private static void osl$blocks$initAndLockBlockRegistry(CallbackInfo ci) {
+		BlockRegistryImpl.init();
+		BlockRegistryImpl.lock();
+	}
+
+	@Override
+	public String toString() {
+		return "Block{" + BlockRegistryImpl.getKey((Block) (Object) this) + "}";
+	}
+
+	@Override
+	public boolean isAir() {
+		return false;
+	}
+}
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlocksMixin.java b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlocksMixin.java
new file mode 100644
index 00000000..1ac4e781
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlocksMixin.java
@@ -0,0 +1,11 @@
+package net.ornithemc.osl.blocks.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+
+import net.minecraft.block.Blocks;
+
+import net.ornithemc.osl.blocks.api.block.BlocksExtension;
+
+@Mixin(Blocks.class)
+public class BlocksMixin implements BlocksExtension {
+}
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/resources/fabric.mod.json b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..e3b47da0
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/resources/fabric.mod.json
@@ -0,0 +1,26 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-blocks",
+  "version": "0.1.0-alpha.1+mc13w36a-mc14w26c",
+  "environment": "*",
+  "mixins": [
+    "osl.blocks.mixins.json"
+  ],
+  "accessWidener": "osl.blocks.classtweaker",
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.7-alpha.13.36.a \u003c\u003d1.8-alpha.14.26.c",
+    "osl-core": "\u003e\u003d0.7.0"
+  },
+  "name": "OSL Blocks",
+  "description": "Blocks API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/resources/osl.blocks.classtweaker b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/resources/osl.blocks.classtweaker
new file mode 100644
index 00000000..e8fc2dcb
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/resources/osl.blocks.classtweaker
@@ -0,0 +1,15 @@
+classTweaker	v1	named
+
+transitive-accessible	method	net/minecraft/block/Block	setSounds	(Lnet/minecraft/block/Block$Sounds;)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setOpacity	(I)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setLight	(F)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setBlastResistance	(F)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setStrength	(F)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setUnbreakable	()Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setTicksRandomly	(Z)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setKey	(Ljava/lang/String;)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setCreativeModeTab	(Lnet/minecraft/item/CreativeModeTab;)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setSpriteName	(Ljava/lang/String;)Lnet/minecraft/block/Block;
+
+transitive-inject-interface	net/minecraft/block/Block	net/ornithemc/osl/blocks/impl/block/BlockExtensionImpl
+transitive-inject-interface	net/minecraft/block/Blocks	net/ornithemc/osl/blocks/impl/block/BlocksExtensionImpl
\ No newline at end of file
diff --git a/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/resources/osl.blocks.mixins.json b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/resources/osl.blocks.mixins.json
new file mode 100644
index 00000000..be211c14
--- /dev/null
+++ b/libraries/blocks/blocks-mc13w36a-mc14w26c/src/main/resources/osl.blocks.mixins.json
@@ -0,0 +1,19 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.blocks.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"plugin": "net.ornithemc.osl.blocks.impl.BlocksMixinPlugin",
+	"mixins": [
+		"common.AirBlockMixin",
+		"common.BlockMixin",
+		"common.BlocksMixin"
+	],
+	"client": [
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/blocks/blocks-mc14w27a-mc17w46a/build.gradle b/libraries/blocks/blocks-mc14w27a-mc17w46a/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/blocks/blocks-mc14w27a-mc17w46a/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/blocks/blocks-mc14w27a-mc17w46a/gradle.properties b/libraries/blocks/blocks-mc14w27a-mc17w46a/gradle.properties
new file mode 100644
index 00000000..5d811d73
--- /dev/null
+++ b/libraries/blocks/blocks-mc14w27a-mc17w46a/gradle.properties
@@ -0,0 +1,5 @@
+min_mc_version = 14w27a
+max_mc_version = 17w46a
+minecraft_dependency = >=1.8-alpha.14.27.a <=1.13-alpha.17.46.a
+
+minecraft_version = 1.12.2
diff --git a/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java
new file mode 100644
index 00000000..c2d7af63
--- /dev/null
+++ b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.blocks.api;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the blocks lifecycle.
+ */
+public final class BlockEvents {
+
+	/**
+	 * This event is invoked upon game start-up, after Vanilla block registration is finished.
+	 * 
+	 * <p>
+	 * Custom block registration should be done in a listener of this event.
+	 * Helper methods for registering blocks can be found in the {@linkplain
+	 * BlockRegistry} class.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * BlockEvents.REGISTER_BLOCKS.register(() -> {
+	 * 	BlockRegistry.register(99, NamespacedIdentifiers.from("example", "cookie"), new CookieBlock());
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see BlockRegistry
+	 */
+	public static final Event<Runnable> REGISTER_BLOCKS = Event.runnable();
+
+}
diff --git a/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java
new file mode 100644
index 00000000..003e6ec5
--- /dev/null
+++ b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java
@@ -0,0 +1,60 @@
+package net.ornithemc.osl.blocks.api;
+
+import java.util.Set;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.impl.BlockRegistryImpl;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+
+/**
+ * Public access to the Blocks registry.
+ */
+public final class BlockRegistry {
+
+	/**
+	 * @return the numerical ID assigned to the given block.
+	 */
+	public static int getId(Block block) {
+		return BlockRegistryImpl.getId(block);
+	}
+
+	/**
+	 * @return the namespaced ID assigned to the given block.
+	 */
+	public static NamespacedIdentifier getKey(Block block) {
+		return BlockRegistryImpl.getKey(block);
+	}
+
+	/**
+	 * @return the block mapped to the given numerical ID.
+	 */
+	public static Block getBlock(int id) {
+		return BlockRegistryImpl.getBlock(id);
+	}
+
+	/**
+	 * @return the block mapped to the given namespaced ID.
+	 */
+	public static Block getBlock(NamespacedIdentifier key) {
+		return BlockRegistryImpl.getBlock(key);
+	}
+
+	/**
+	 * @return a set containing all namespaced IDs in the registry.
+	 */
+	public static Set<NamespacedIdentifier> keySet() {
+		return BlockRegistryImpl.keySet();
+	}
+
+	/**
+	 * @param <T>   the block type.
+	 * @param id    the numerical ID of the block.
+	 * @param key   the namespaced ID of the block.
+	 * @param block the block to register.
+	 * @return the registered  block.
+	 */
+	public static <T extends Block> T register(int id, NamespacedIdentifier key, T block) {
+		return BlockRegistryImpl.register(id, key, block);
+	}
+}
diff --git a/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/api/block/BlockExtension.java b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/api/block/BlockExtension.java
new file mode 100644
index 00000000..d3cc82ed
--- /dev/null
+++ b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/api/block/BlockExtension.java
@@ -0,0 +1,10 @@
+package net.ornithemc.osl.blocks.api.block;
+
+public interface BlockExtension {
+
+	/**
+	 * @return whether this block is air.
+	 */
+	boolean isAir();
+
+}
diff --git a/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java
new file mode 100644
index 00000000..28736445
--- /dev/null
+++ b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java
@@ -0,0 +1,75 @@
+package net.ornithemc.osl.blocks.impl;
+
+import java.util.Collections;
+import java.util.Set;
+
+import net.minecraft.block.Block;
+import net.minecraft.resource.Identifier;
+
+import net.ornithemc.osl.blocks.api.BlockEvents;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+
+public final class BlockRegistryImpl {
+
+	private static boolean locked = true;
+	private static boolean initialized = false;
+
+	public static int getId(Block block) {
+		return Block.REGISTRY.getId(block);
+	}
+
+	public static NamespacedIdentifier getKey(Block block) {
+		return Block.REGISTRY.getKey(block);
+	}
+
+	public static Block getBlock(int id) {
+		return Block.REGISTRY.get(id);
+	}
+
+	public static Block getBlock(NamespacedIdentifier key) {
+		return Block.REGISTRY.get(identifier(key));
+	}
+
+	public static Set<NamespacedIdentifier> keySet() {
+		return Collections.unmodifiableSet(Block.REGISTRY.keySet());
+	}
+
+	public static <T extends Block> T register(int id, NamespacedIdentifier key, T block) {
+		if (locked) {
+			throw new IllegalStateException("register called too " + (initialized ? "late" : "early") + ": registry locked!");
+		} else {
+			Block.REGISTRY.register(id, identifier(key), block);
+		}
+
+		return block;
+	}
+
+	private static Identifier identifier(NamespacedIdentifier id) {
+		return id instanceof Identifier ? (Identifier) id : new Identifier(id.namespace(), id.identifier());
+	}
+
+	public static void lock() {
+		if (!initialized) {
+			throw new IllegalStateException("cannot lock block registry unless it's been initialized!");
+		}
+
+		locked = true;
+	}
+
+	public static void unlock() {
+		if (initialized) {
+			throw new IllegalStateException("cannot unlock block registry once it's been initialized!");
+		}
+
+		locked = false;
+	}
+
+	public static void init() {
+		if (locked) {
+			throw new IllegalStateException("cannot initialize block registry when it's locked!");
+		}
+
+		BlockEvents.REGISTER_BLOCKS.invoker().run();
+		initialized = true;
+	}
+}
diff --git a/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/impl/block/BlockExtensionImpl.java b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/impl/block/BlockExtensionImpl.java
new file mode 100644
index 00000000..5f35a77d
--- /dev/null
+++ b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/impl/block/BlockExtensionImpl.java
@@ -0,0 +1,11 @@
+package net.ornithemc.osl.blocks.impl.block;
+
+import net.ornithemc.osl.blocks.api.block.BlockExtension;
+
+public interface BlockExtensionImpl extends BlockExtension {
+
+	@Override
+	default boolean isAir() {
+		throw new AbstractMethodError();
+	}
+}
diff --git a/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/AirBlockMixin.java b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/AirBlockMixin.java
new file mode 100644
index 00000000..0fd9972c
--- /dev/null
+++ b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/AirBlockMixin.java
@@ -0,0 +1,16 @@
+package net.ornithemc.osl.blocks.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+
+import net.minecraft.block.AirBlock;
+
+import net.ornithemc.osl.blocks.api.block.BlockExtension;
+
+@Mixin(AirBlock.class)
+public class AirBlockMixin implements BlockExtension {
+
+	@Override
+	public boolean isAir() {
+		return true;
+	}
+}
diff --git a/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java
new file mode 100644
index 00000000..6b4e6bf5
--- /dev/null
+++ b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java
@@ -0,0 +1,42 @@
+package net.ornithemc.osl.blocks.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.api.block.BlockExtension;
+import net.ornithemc.osl.blocks.impl.BlockRegistryImpl;
+
+@Mixin(Block.class)
+public class BlockMixin implements BlockExtension {
+
+	@Inject(
+		method = "init",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private static void osl$blocks$unlockBlockRegistry(CallbackInfo ci) {
+		BlockRegistryImpl.unlock();
+	}
+
+	@Inject(
+		method = "init",
+		at = @At(
+			value = "INVOKE",
+			target = "Lnet/minecraft/util/registry/DefaultedIdRegistry;validate()V"
+		)
+	)
+	private static void osl$blocks$initAndLockBlockRegistry(CallbackInfo ci) {
+		BlockRegistryImpl.init();
+		BlockRegistryImpl.lock();
+	}
+
+	@Override
+	public boolean isAir() {
+		return false;
+	}
+}
diff --git a/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/resources/fabric.mod.json b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..743fdf5f
--- /dev/null
+++ b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/resources/fabric.mod.json
@@ -0,0 +1,26 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-blocks",
+  "version": "0.1.0-alpha.1+mc14w27a-mc17w46a",
+  "environment": "*",
+  "mixins": [
+    "osl.blocks.mixins.json"
+  ],
+  "accessWidener": "osl.blocks.classtweaker",
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.8-alpha.14.27.a \u003c\u003d1.13-alpha.17.46.a",
+    "osl-core": "\u003e\u003d0.7.0"
+  },
+  "name": "OSL Blocks",
+  "description": "Blocks API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/resources/osl.blocks.classtweaker b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/resources/osl.blocks.classtweaker
new file mode 100644
index 00000000..324b5d4a
--- /dev/null
+++ b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/resources/osl.blocks.classtweaker
@@ -0,0 +1,14 @@
+classTweaker	v1	named
+
+transitive-accessible	method	net/minecraft/block/Block	setSounds	(Lnet/minecraft/block/sound/BlockSounds;)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setOpacity	(I)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setLight	(F)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setBlastResistance	(F)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setStrength	(F)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setUnbreakable	()Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setTicksRandomly	(Z)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setKey	(Ljava/lang/String;)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	disableStats	()Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setCreativeModeTab	(Lnet/minecraft/item/CreativeModeTab;)Lnet/minecraft/block/Block;
+
+transitive-inject-interface	net/minecraft/block/Block	net/ornithemc/osl/blocks/impl/block/BlockExtensionImpl
\ No newline at end of file
diff --git a/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/resources/osl.blocks.mixins.json b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/resources/osl.blocks.mixins.json
new file mode 100644
index 00000000..7f2c19c8
--- /dev/null
+++ b/libraries/blocks/blocks-mc14w27a-mc17w46a/src/main/resources/osl.blocks.mixins.json
@@ -0,0 +1,17 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.blocks.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+		"common.AirBlockMixin",
+		"common.BlockMixin"
+	],
+	"client": [
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/blocks/blocks-mc17w47a-mc18w31a/build.gradle b/libraries/blocks/blocks-mc17w47a-mc18w31a/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/blocks/blocks-mc17w47a-mc18w31a/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/blocks/blocks-mc17w47a-mc18w31a/gradle.properties b/libraries/blocks/blocks-mc17w47a-mc18w31a/gradle.properties
new file mode 100644
index 00000000..214f5d68
--- /dev/null
+++ b/libraries/blocks/blocks-mc17w47a-mc18w31a/gradle.properties
@@ -0,0 +1,5 @@
+min_mc_version = 17w47a
+max_mc_version = 18w31a
+minecraft_dependency = >=1.13-alpha.17.47.a <=1.13.1-alpha.18.31.a
+
+minecraft_version = 1.13
diff --git a/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java b/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java
new file mode 100644
index 00000000..9a76f18b
--- /dev/null
+++ b/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.blocks.api;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the blocks lifecycle.
+ */
+public final class BlockEvents {
+
+	/**
+	 * This event is invoked upon game start-up, after Vanilla block registration is finished.
+	 * 
+	 * <p>
+	 * Custom block registration should be done in a listener of this event.
+	 * Helper methods for registering blocks can be found in the {@linkplain
+	 * BlockRegistry} class.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * BlockEvents.REGISTER_BLOCKS.register(() -> {
+	 * 	BlockRegistry.register(NamespacedIdentifiers.from("example", "cookie"), new CookieBlock());
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see BlockRegistry
+	 */
+	public static final Event<Runnable> REGISTER_BLOCKS = Event.runnable();
+
+}
diff --git a/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java b/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java
new file mode 100644
index 00000000..96500cd9
--- /dev/null
+++ b/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java
@@ -0,0 +1,59 @@
+package net.ornithemc.osl.blocks.api;
+
+import java.util.Set;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.impl.BlockRegistryImpl;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+
+/**
+ * Public access to the Blocks registry.
+ */
+public final class BlockRegistry {
+
+	/**
+	 * @return the numerical ID assigned to the given block.
+	 */
+	public static int getId(Block block) {
+		return BlockRegistryImpl.getId(block);
+	}
+
+	/**
+	 * @return the namespaced ID assigned to the given block.
+	 */
+	public static NamespacedIdentifier getKey(Block block) {
+		return BlockRegistryImpl.getKey(block);
+	}
+
+	/**
+	 * @return the block mapped to the given numerical ID.
+	 */
+	public static Block getBlock(int id) {
+		return BlockRegistryImpl.getBlock(id);
+	}
+
+	/**
+	 * @return the block mapped to the given namespaced ID.
+	 */
+	public static Block getBlock(NamespacedIdentifier key) {
+		return BlockRegistryImpl.getBlock(key);
+	}
+
+	/**
+	 * @return a set containing all namespaced IDs in the registry.
+	 */
+	public static Set<NamespacedIdentifier> keySet() {
+		return BlockRegistryImpl.keySet();
+	}
+
+	/**
+	 * @param <T>   the block type.
+	 * @param key   the namespaced ID of the block.
+	 * @param block the block to register.
+	 * @return the registered  block.
+	 */
+	public static <T extends Block> T register(NamespacedIdentifier key, T block) {
+		return BlockRegistryImpl.register(key, block);
+	}
+}
diff --git a/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java b/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java
new file mode 100644
index 00000000..3f168bd4
--- /dev/null
+++ b/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java
@@ -0,0 +1,75 @@
+package net.ornithemc.osl.blocks.impl;
+
+import java.util.Collections;
+import java.util.Set;
+
+import net.minecraft.block.Block;
+import net.minecraft.resource.Identifier;
+
+import net.ornithemc.osl.blocks.api.BlockEvents;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+
+public final class BlockRegistryImpl {
+
+	private static boolean locked = true;
+	private static boolean initialized = false;
+
+	public static int getId(Block block) {
+		return Block.REGISTRY.getId(block);
+	}
+
+	public static NamespacedIdentifier getKey(Block block) {
+		return Block.REGISTRY.getKey(block);
+	}
+
+	public static Block getBlock(int id) {
+		return Block.REGISTRY.get(id);
+	}
+
+	public static Block getBlock(NamespacedIdentifier key) {
+		return Block.REGISTRY.get(identifier(key));
+	}
+
+	public static Set<NamespacedIdentifier> keySet() {
+		return Collections.unmodifiableSet(Block.REGISTRY.entrySet());
+	}
+
+	public static <T extends Block> T register(NamespacedIdentifier key, T block) {
+		if (locked) {
+			throw new IllegalStateException("register called too " + (initialized ? "late" : "early") + ": registry locked!");
+		} else {
+			Block.REGISTRY.put(identifier(key), block);
+		}
+
+		return block;
+	}
+
+	private static Identifier identifier(NamespacedIdentifier id) {
+		return id instanceof Identifier ? (Identifier) id : new Identifier(id.namespace(), id.identifier());
+	}
+
+	public static void lock() {
+		if (!initialized) {
+			throw new IllegalStateException("cannot lock block registry unless it's been initialized!");
+		}
+
+		locked = true;
+	}
+
+	public static void unlock() {
+		if (initialized) {
+			throw new IllegalStateException("cannot unlock block registry once it's been initialized!");
+		}
+
+		locked = false;
+	}
+
+	public static void init() {
+		if (locked) {
+			throw new IllegalStateException("cannot initialize block registry when it's locked!");
+		}
+
+		BlockEvents.REGISTER_BLOCKS.invoker().run();
+		initialized = true;
+	}
+}
diff --git a/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java b/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java
new file mode 100644
index 00000000..17924f83
--- /dev/null
+++ b/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java
@@ -0,0 +1,45 @@
+package net.ornithemc.osl.blocks.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.At.Shift;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.Slice;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.impl.BlockRegistryImpl;
+
+@Mixin(Block.class)
+public class BlockMixin {
+
+	@Inject(
+		method = "init",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private static void osl$blocks$unlockBlockRegistry(CallbackInfo ci) {
+		BlockRegistryImpl.unlock();
+	}
+
+	@Inject(
+		method = "init",
+		slice = @Slice(
+			from = @At(
+				value = "CONSTANT",
+				args = "stringValue=structure_block" // last block to be registered
+			)
+		),
+		at = @At(
+			value = "INVOKE",
+			target = "Lnet/minecraft/block/Block;register(Ljava/lang/String;Lnet/minecraft/block/Block;)V",
+			shift = Shift.AFTER
+		)
+	)
+	private static void osl$blocks$initAndLockBlockRegistry(CallbackInfo ci) {
+		BlockRegistryImpl.init();
+		BlockRegistryImpl.lock();
+	}
+}
diff --git a/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/resources/fabric.mod.json b/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..f8bd20d7
--- /dev/null
+++ b/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/resources/fabric.mod.json
@@ -0,0 +1,25 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-blocks",
+  "version": "0.1.0-alpha.1+mc17w47a-mc18w31a",
+  "environment": "*",
+  "mixins": [
+    "osl.blocks.mixins.json"
+  ],
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.13-alpha.17.47.a \u003c\u003d1.13.1-alpha.18.31.a",
+    "osl-core": "\u003e\u003d0.7.0"
+  },
+  "name": "OSL Blocks",
+  "description": "Blocks API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/resources/osl.blocks.mixins.json b/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/resources/osl.blocks.mixins.json
new file mode 100644
index 00000000..bfd6b26f
--- /dev/null
+++ b/libraries/blocks/blocks-mc17w47a-mc18w31a/src/main/resources/osl.blocks.mixins.json
@@ -0,0 +1,16 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.blocks.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+		"common.BlockMixin"
+	],
+	"client": [
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/blocks/blocks-mc18w32a-mc1.13.2/build.gradle b/libraries/blocks/blocks-mc18w32a-mc1.13.2/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w32a-mc1.13.2/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/blocks/blocks-mc18w32a-mc1.13.2/gradle.properties b/libraries/blocks/blocks-mc18w32a-mc1.13.2/gradle.properties
new file mode 100644
index 00000000..4c9c2619
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w32a-mc1.13.2/gradle.properties
@@ -0,0 +1,5 @@
+min_mc_version = 18w32a
+max_mc_version = 1.13.2
+minecraft_dependency = >=1.13.1-alpha.18.32.a <=1.13.2
+
+minecraft_version = 1.13.2
diff --git a/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java b/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java
new file mode 100644
index 00000000..9a76f18b
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.blocks.api;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the blocks lifecycle.
+ */
+public final class BlockEvents {
+
+	/**
+	 * This event is invoked upon game start-up, after Vanilla block registration is finished.
+	 * 
+	 * <p>
+	 * Custom block registration should be done in a listener of this event.
+	 * Helper methods for registering blocks can be found in the {@linkplain
+	 * BlockRegistry} class.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * BlockEvents.REGISTER_BLOCKS.register(() -> {
+	 * 	BlockRegistry.register(NamespacedIdentifiers.from("example", "cookie"), new CookieBlock());
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see BlockRegistry
+	 */
+	public static final Event<Runnable> REGISTER_BLOCKS = Event.runnable();
+
+}
diff --git a/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java b/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java
new file mode 100644
index 00000000..96500cd9
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java
@@ -0,0 +1,59 @@
+package net.ornithemc.osl.blocks.api;
+
+import java.util.Set;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.impl.BlockRegistryImpl;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+
+/**
+ * Public access to the Blocks registry.
+ */
+public final class BlockRegistry {
+
+	/**
+	 * @return the numerical ID assigned to the given block.
+	 */
+	public static int getId(Block block) {
+		return BlockRegistryImpl.getId(block);
+	}
+
+	/**
+	 * @return the namespaced ID assigned to the given block.
+	 */
+	public static NamespacedIdentifier getKey(Block block) {
+		return BlockRegistryImpl.getKey(block);
+	}
+
+	/**
+	 * @return the block mapped to the given numerical ID.
+	 */
+	public static Block getBlock(int id) {
+		return BlockRegistryImpl.getBlock(id);
+	}
+
+	/**
+	 * @return the block mapped to the given namespaced ID.
+	 */
+	public static Block getBlock(NamespacedIdentifier key) {
+		return BlockRegistryImpl.getBlock(key);
+	}
+
+	/**
+	 * @return a set containing all namespaced IDs in the registry.
+	 */
+	public static Set<NamespacedIdentifier> keySet() {
+		return BlockRegistryImpl.keySet();
+	}
+
+	/**
+	 * @param <T>   the block type.
+	 * @param key   the namespaced ID of the block.
+	 * @param block the block to register.
+	 * @return the registered  block.
+	 */
+	public static <T extends Block> T register(NamespacedIdentifier key, T block) {
+		return BlockRegistryImpl.register(key, block);
+	}
+}
diff --git a/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java b/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java
new file mode 100644
index 00000000..374e98f7
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java
@@ -0,0 +1,76 @@
+package net.ornithemc.osl.blocks.impl;
+
+import java.util.Collections;
+import java.util.Set;
+
+import net.minecraft.block.Block;
+import net.minecraft.resource.Identifier;
+import net.minecraft.util.registry.Registry;
+
+import net.ornithemc.osl.blocks.api.BlockEvents;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+
+public final class BlockRegistryImpl {
+
+	private static boolean locked = true;
+	private static boolean initialized = false;
+
+	public static int getId(Block block) {
+		return Registry.BLOCK.getId(block);
+	}
+
+	public static NamespacedIdentifier getKey(Block block) {
+		return Registry.BLOCK.getKey(block);
+	}
+
+	public static Block getBlock(int id) {
+		return Registry.BLOCK.get(id);
+	}
+
+	public static Block getBlock(NamespacedIdentifier key) {
+		return Registry.BLOCK.get(identifier(key));
+	}
+
+	public static Set<NamespacedIdentifier> keySet() {
+		return Collections.unmodifiableSet(Registry.BLOCK.keySet());
+	}
+
+	public static <T extends Block> T register(NamespacedIdentifier key, T block) {
+		if (locked) {
+			throw new IllegalStateException("register called too " + (initialized ? "late" : "early") + ": registry locked!");
+		} else {
+			Registry.BLOCK.register(identifier(key), block);
+		}
+
+		return block;
+	}
+
+	private static Identifier identifier(NamespacedIdentifier id) {
+		return id instanceof Identifier ? (Identifier) id : new Identifier(id.namespace(), id.identifier());
+	}
+
+	public static void lock() {
+		if (!initialized) {
+			throw new IllegalStateException("cannot lock block registry unless it's been initialized!");
+		}
+
+		locked = true;
+	}
+
+	public static void unlock() {
+		if (initialized) {
+			throw new IllegalStateException("cannot unlock block registry once it's been initialized!");
+		}
+
+		locked = false;
+	}
+
+	public static void init() {
+		if (locked) {
+			throw new IllegalStateException("cannot initialize block registry when it's locked!");
+		}
+
+		BlockEvents.REGISTER_BLOCKS.invoker().run();
+		initialized = true;
+	}
+}
diff --git a/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java b/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java
new file mode 100644
index 00000000..17924f83
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java
@@ -0,0 +1,45 @@
+package net.ornithemc.osl.blocks.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.At.Shift;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.Slice;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.impl.BlockRegistryImpl;
+
+@Mixin(Block.class)
+public class BlockMixin {
+
+	@Inject(
+		method = "init",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private static void osl$blocks$unlockBlockRegistry(CallbackInfo ci) {
+		BlockRegistryImpl.unlock();
+	}
+
+	@Inject(
+		method = "init",
+		slice = @Slice(
+			from = @At(
+				value = "CONSTANT",
+				args = "stringValue=structure_block" // last block to be registered
+			)
+		),
+		at = @At(
+			value = "INVOKE",
+			target = "Lnet/minecraft/block/Block;register(Ljava/lang/String;Lnet/minecraft/block/Block;)V",
+			shift = Shift.AFTER
+		)
+	)
+	private static void osl$blocks$initAndLockBlockRegistry(CallbackInfo ci) {
+		BlockRegistryImpl.init();
+		BlockRegistryImpl.lock();
+	}
+}
diff --git a/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/resources/fabric.mod.json b/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..d904a7e3
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/resources/fabric.mod.json
@@ -0,0 +1,25 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-blocks",
+  "version": "0.1.0-alpha.1+mc18w32a-mc1.13.2",
+  "environment": "*",
+  "mixins": [
+    "osl.blocks.mixins.json"
+  ],
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.13.1-alpha.18.32.a \u003c\u003d1.13.2",
+    "osl-core": "\u003e\u003d0.7.0"
+  },
+  "name": "OSL Blocks",
+  "description": "Blocks API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/resources/osl.blocks.mixins.json b/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/resources/osl.blocks.mixins.json
new file mode 100644
index 00000000..bfd6b26f
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w32a-mc1.13.2/src/main/resources/osl.blocks.mixins.json
@@ -0,0 +1,16 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.blocks.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+		"common.BlockMixin"
+	],
+	"client": [
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/blocks/blocks-mc18w43a-mc1.14.4/build.gradle b/libraries/blocks/blocks-mc18w43a-mc1.14.4/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w43a-mc1.14.4/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/blocks/blocks-mc18w43a-mc1.14.4/gradle.properties b/libraries/blocks/blocks-mc18w43a-mc1.14.4/gradle.properties
new file mode 100644
index 00000000..071d210e
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w43a-mc1.14.4/gradle.properties
@@ -0,0 +1,5 @@
+min_mc_version = 18w43a
+max_mc_version = 1.14.4
+minecraft_dependency = >=1.14-alpha.18.43.a <=1.14.4
+
+minecraft_version = 1.14.4
diff --git a/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java b/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java
new file mode 100644
index 00000000..9a76f18b
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.blocks.api;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the blocks lifecycle.
+ */
+public final class BlockEvents {
+
+	/**
+	 * This event is invoked upon game start-up, after Vanilla block registration is finished.
+	 * 
+	 * <p>
+	 * Custom block registration should be done in a listener of this event.
+	 * Helper methods for registering blocks can be found in the {@linkplain
+	 * BlockRegistry} class.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * BlockEvents.REGISTER_BLOCKS.register(() -> {
+	 * 	BlockRegistry.register(NamespacedIdentifiers.from("example", "cookie"), new CookieBlock());
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see BlockRegistry
+	 */
+	public static final Event<Runnable> REGISTER_BLOCKS = Event.runnable();
+
+}
diff --git a/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java b/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java
new file mode 100644
index 00000000..96500cd9
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java
@@ -0,0 +1,59 @@
+package net.ornithemc.osl.blocks.api;
+
+import java.util.Set;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.impl.BlockRegistryImpl;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+
+/**
+ * Public access to the Blocks registry.
+ */
+public final class BlockRegistry {
+
+	/**
+	 * @return the numerical ID assigned to the given block.
+	 */
+	public static int getId(Block block) {
+		return BlockRegistryImpl.getId(block);
+	}
+
+	/**
+	 * @return the namespaced ID assigned to the given block.
+	 */
+	public static NamespacedIdentifier getKey(Block block) {
+		return BlockRegistryImpl.getKey(block);
+	}
+
+	/**
+	 * @return the block mapped to the given numerical ID.
+	 */
+	public static Block getBlock(int id) {
+		return BlockRegistryImpl.getBlock(id);
+	}
+
+	/**
+	 * @return the block mapped to the given namespaced ID.
+	 */
+	public static Block getBlock(NamespacedIdentifier key) {
+		return BlockRegistryImpl.getBlock(key);
+	}
+
+	/**
+	 * @return a set containing all namespaced IDs in the registry.
+	 */
+	public static Set<NamespacedIdentifier> keySet() {
+		return BlockRegistryImpl.keySet();
+	}
+
+	/**
+	 * @param <T>   the block type.
+	 * @param key   the namespaced ID of the block.
+	 * @param block the block to register.
+	 * @return the registered  block.
+	 */
+	public static <T extends Block> T register(NamespacedIdentifier key, T block) {
+		return BlockRegistryImpl.register(key, block);
+	}
+}
diff --git a/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java b/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java
new file mode 100644
index 00000000..790b4b72
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java
@@ -0,0 +1,74 @@
+package net.ornithemc.osl.blocks.impl;
+
+import java.util.Collections;
+import java.util.Set;
+
+import net.minecraft.block.Block;
+import net.minecraft.resource.Identifier;
+import net.minecraft.util.registry.Registry;
+
+import net.ornithemc.osl.blocks.api.BlockEvents;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+
+public final class BlockRegistryImpl {
+
+	private static boolean locked = true;
+	private static boolean initialized = false;
+
+	public static int getId(Block block) {
+		return Registry.BLOCK.getId(block);
+	}
+
+	public static NamespacedIdentifier getKey(Block block) {
+		return Registry.BLOCK.getKey(block);
+	}
+
+	public static Block getBlock(int id) {
+		return Registry.BLOCK.get(id);
+	}
+
+	public static Block getBlock(NamespacedIdentifier key) {
+		return Registry.BLOCK.getOrDefault(identifier(key));
+	}
+
+	public static Set<NamespacedIdentifier> keySet() {
+		return Collections.unmodifiableSet(Registry.BLOCK.keySet());
+	}
+
+	public static <T extends Block> T register(NamespacedIdentifier key, T block) {
+		if (locked) {
+			throw new IllegalStateException("register called too " + (initialized ? "late" : "early") + ": registry locked!");
+		} else {
+			return Registry.BLOCK.m_30368144(identifier(key), block);
+		}
+	}
+
+	private static Identifier identifier(NamespacedIdentifier id) {
+		return id instanceof Identifier ? (Identifier) id : new Identifier(id.namespace(), id.identifier());
+	}
+
+	public static void lock() {
+		if (!initialized) {
+			throw new IllegalStateException("cannot lock block registry unless it's been initialized!");
+		}
+
+		locked = true;
+	}
+
+	public static void unlock() {
+		if (initialized) {
+			throw new IllegalStateException("cannot unlock block registry once it's been initialized!");
+		}
+
+		locked = false;
+	}
+
+	public static void init() {
+		if (locked) {
+			throw new IllegalStateException("cannot initialize block registry when it's locked!");
+		}
+
+		BlockEvents.REGISTER_BLOCKS.invoker().run();
+		initialized = true;
+	}
+}
diff --git a/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlocksMixin.java b/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlocksMixin.java
new file mode 100644
index 00000000..27b3d23c
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlocksMixin.java
@@ -0,0 +1,36 @@
+package net.ornithemc.osl.blocks.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.block.Blocks;
+
+import net.ornithemc.osl.blocks.impl.BlockRegistryImpl;
+
+@Mixin(Blocks.class)
+public class BlocksMixin {
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private static void osl$blocks$unlockBlockRegistry(CallbackInfo ci) {
+		BlockRegistryImpl.unlock();
+	}
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "FIELD",
+			target = "Lnet/minecraft/util/registry/Registry;BLOCK:Lnet/minecraft/util/registry/DefaultedIdRegistry;"
+		)
+	)
+	private static void osl$blocks$initAndLockBlockRegistry(CallbackInfo ci) {
+		BlockRegistryImpl.init();
+		BlockRegistryImpl.lock();
+	}
+}
diff --git a/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/resources/fabric.mod.json b/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..9d9ff023
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/resources/fabric.mod.json
@@ -0,0 +1,25 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-blocks",
+  "version": "0.1.0-alpha.1+mc18w43a-mc1.14.4",
+  "environment": "*",
+  "mixins": [
+    "osl.blocks.mixins.json"
+  ],
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.14-alpha.18.43.a \u003c\u003d1.14.4",
+    "osl-core": "\u003e\u003d0.7.0"
+  },
+  "name": "OSL Blocks",
+  "description": "Blocks API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/resources/osl.blocks.mixins.json b/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/resources/osl.blocks.mixins.json
new file mode 100644
index 00000000..c958d77d
--- /dev/null
+++ b/libraries/blocks/blocks-mc18w43a-mc1.14.4/src/main/resources/osl.blocks.mixins.json
@@ -0,0 +1,16 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.blocks.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"mixins": [
+		"common.BlocksMixin"
+	],
+	"client": [
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/build.gradle b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/build.gradle
new file mode 100644
index 00000000..0a350fdb
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/build.gradle
@@ -0,0 +1 @@
+setUpModule(project)
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/gradle.properties b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/gradle.properties
new file mode 100644
index 00000000..48fac24e
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/gradle.properties
@@ -0,0 +1,8 @@
+min_mc_version = a1.0.1_01
+max_mc_version = 1.6.4
+minecraft_dependency = >=1.0.0-alpha.0.1 <=1.6.4
+
+minecraft_version = 1.6.4
+raven_build = 1
+sparrow_build = 1
+nests_build = 3
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java
new file mode 100644
index 00000000..34ca2a82
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/api/BlockEvents.java
@@ -0,0 +1,34 @@
+package net.ornithemc.osl.blocks.api;
+
+import net.ornithemc.osl.core.api.events.Event;
+
+/**
+ * Events related to the blocks lifecycle.
+ */
+public final class BlockEvents {
+
+	/**
+	 * This event is invoked upon game start-up, after Vanilla block registration is finished.
+	 * 
+	 * <p>
+	 * Custom block registration should be done in a listener of this event.
+	 * Helper methods for registering blocks can be found in the {@linkplain
+	 * BlockRegistry} class.
+	 * 
+	 * <p>
+	 * Listeners to this event should be registered in your mod's entrypoint,
+	 * and can be done as follows:
+	 * 
+	 * <pre>
+	 * {@code
+	 * BlockEvents.REGISTER_BLOCKS.register(() -> {
+	 * 	BlockRegistry.register(99, NamespacedIdentifiers.from("example", "cookie"), new CookieBlock(99));
+	 * });
+	 * }
+	 * </pre>
+	 * 
+	 * @see BlockRegistry
+	 */
+	public static final Event<Runnable> REGISTER_BLOCKS = Event.runnable();
+
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java
new file mode 100644
index 00000000..003e6ec5
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/api/BlockRegistry.java
@@ -0,0 +1,60 @@
+package net.ornithemc.osl.blocks.api;
+
+import java.util.Set;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.impl.BlockRegistryImpl;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+
+/**
+ * Public access to the Blocks registry.
+ */
+public final class BlockRegistry {
+
+	/**
+	 * @return the numerical ID assigned to the given block.
+	 */
+	public static int getId(Block block) {
+		return BlockRegistryImpl.getId(block);
+	}
+
+	/**
+	 * @return the namespaced ID assigned to the given block.
+	 */
+	public static NamespacedIdentifier getKey(Block block) {
+		return BlockRegistryImpl.getKey(block);
+	}
+
+	/**
+	 * @return the block mapped to the given numerical ID.
+	 */
+	public static Block getBlock(int id) {
+		return BlockRegistryImpl.getBlock(id);
+	}
+
+	/**
+	 * @return the block mapped to the given namespaced ID.
+	 */
+	public static Block getBlock(NamespacedIdentifier key) {
+		return BlockRegistryImpl.getBlock(key);
+	}
+
+	/**
+	 * @return a set containing all namespaced IDs in the registry.
+	 */
+	public static Set<NamespacedIdentifier> keySet() {
+		return BlockRegistryImpl.keySet();
+	}
+
+	/**
+	 * @param <T>   the block type.
+	 * @param id    the numerical ID of the block.
+	 * @param key   the namespaced ID of the block.
+	 * @param block the block to register.
+	 * @return the registered  block.
+	 */
+	public static <T extends Block> T register(int id, NamespacedIdentifier key, T block) {
+		return BlockRegistryImpl.register(id, key, block);
+	}
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/api/block/BlockExtension.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/api/block/BlockExtension.java
new file mode 100644
index 00000000..9d9950d5
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/api/block/BlockExtension.java
@@ -0,0 +1,17 @@
+package net.ornithemc.osl.blocks.api.block;
+
+import net.minecraft.block.Block;
+
+public interface BlockExtension {
+
+	/**
+	 * @return whether this block is air.
+	 */
+	boolean isAir();
+
+	/**
+	 * @return whether this block is the same as the given block.
+	 */
+	boolean is(Block block);
+
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/api/block/Blocks.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/api/block/Blocks.java
new file mode 100644
index 00000000..ee036a38
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/api/block/Blocks.java
@@ -0,0 +1,11 @@
+package net.ornithemc.osl.blocks.api.block;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.impl.block.AirBlock;
+
+public final class Blocks {
+
+	public static final Block AIR = new AirBlock();
+
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java
new file mode 100644
index 00000000..be4e8bee
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/BlockRegistryImpl.java
@@ -0,0 +1,74 @@
+package net.ornithemc.osl.blocks.impl;
+
+import java.util.Set;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.api.BlockEvents;
+import net.ornithemc.osl.core.api.registry.SimpleIdRegistry;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+
+public final class BlockRegistryImpl {
+
+	private static final SimpleIdRegistry<Block> REGISTRY = new SimpleIdRegistry<>();
+
+	private static boolean locked = true;
+	private static boolean initialized = false;
+
+	public static int getId(Block block) {
+		return REGISTRY.getId(block);
+	}
+
+	public static NamespacedIdentifier getKey(Block block) {
+		return REGISTRY.getKey(block);
+	}
+
+	public static Block getBlock(int id) {
+		return REGISTRY.get(id);
+	}
+
+	public static Block getBlock(NamespacedIdentifier key) {
+		return REGISTRY.get(key);
+	}
+
+	public static Set<NamespacedIdentifier> keySet() {
+		return REGISTRY.keySet();
+	}
+
+	public static <T extends Block> T register(int id, NamespacedIdentifier key, T block) {
+		if (locked) {
+			throw new IllegalStateException("register called too " + (initialized ? "late" : "early") + ": registry locked!");
+		} else {
+			REGISTRY.register(id, key, block);
+
+		}
+
+		return block;
+	}
+
+	public static void lock() {
+		if (!initialized) {
+			throw new IllegalStateException("cannot lock block registry unless it's been initialized!");
+		}
+
+		locked = true;
+	}
+
+	public static void unlock() {
+		if (initialized) {
+			throw new IllegalStateException("cannot unlock block registry once it's been initialized!");
+		}
+
+		locked = false;
+	}
+
+	public static void init() {
+		if (locked) {
+			throw new IllegalStateException("cannot initialize block registry when it's locked!");
+		}
+
+		VanillaBlocks.init();
+		BlockEvents.REGISTER_BLOCKS.invoker().run();
+		initialized = true;
+	}
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/BlocksMixinPlugin.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/BlocksMixinPlugin.java
new file mode 100644
index 00000000..62a96841
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/BlocksMixinPlugin.java
@@ -0,0 +1,60 @@
+package net.ornithemc.osl.blocks.impl;
+
+import java.util.List;
+import java.util.Set;
+
+import org.objectweb.asm.tree.ClassNode;
+
+import org.spongepowered.asm.mixin.extensibility.IMixinConfigPlugin;
+import org.spongepowered.asm.mixin.extensibility.IMixinInfo;
+
+import net.ornithemc.osl.core.impl.util.MinecraftVersion;
+
+public class BlocksMixinPlugin implements IMixinConfigPlugin {
+
+	public static final boolean BLOCK_IS_METHOD_PRESENT = MinecraftVersion.resolve().compareTo("13w01a") >= 0;
+
+	@Override
+	public void onLoad(String mixinPackage) {
+	}
+
+	@Override
+	public String getRefMapperConfig() {
+		return null;
+	}
+
+	@Override
+	public boolean shouldApplyMixin(String targetClassName, String mixinClassName) {
+		if ("net.ornithemc.osl.blocks.impl.mixin.common.BlockMixinNew".equals(mixinClassName)) {
+			return BLOCK_IS_METHOD_PRESENT;
+		}
+		if ("net.ornithemc.osl.blocks.impl.mixin.common.BlockMixinOld".equals(mixinClassName)) {
+			return !BLOCK_IS_METHOD_PRESENT;
+		}
+		if ("net.ornithemc.osl.blocks.impl.mixin.common.RedstoneTorchBlockMixin".equals(mixinClassName)) {
+			return !BLOCK_IS_METHOD_PRESENT && MinecraftVersion.resolve().compareTo("a1.0.1") >= 0;
+		}
+		if ("net.ornithemc.osl.blocks.impl.mixin.common.RepeaterBlockMixin".equals(mixinClassName)) {
+			return !BLOCK_IS_METHOD_PRESENT && MinecraftVersion.resolve().compareTo("b1.3") >= 0;
+		}
+
+		return true;
+	}
+
+	@Override
+	public void acceptTargets(Set<String> myTargets, Set<String> otherTargets) {
+	}
+
+	@Override
+	public List<String> getMixins() {
+		return null;
+	}
+
+	@Override
+	public void preApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+	}
+
+	@Override
+	public void postApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+	}
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/VanillaBlocks.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/VanillaBlocks.java
new file mode 100644
index 00000000..b5f66e7a
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/VanillaBlocks.java
@@ -0,0 +1,245 @@
+package net.ornithemc.osl.blocks.impl;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.api.block.Blocks;
+import net.ornithemc.osl.core.api.util.NamespacedIdentifiers;
+
+final class VanillaBlocks {
+
+	/**
+	 * Namespaced IDs were introduced in 1.7. Before then, the numerical IDs
+	 * were the only unique identifiers for blocks. Here we assign namespaced
+	 * IDs to pre-1.7 blocks, matching the 1.7 IDs  where possible.
+	 * <p>
+	 * Note that in 1.7 snapshots the IDs went through several changes.
+	 * The IDs used here match those used in Release 1.7.2.
+	 */
+	private static final String[] IDENTIFIERS = {
+		// grouped per 10 for easier lookup
+
+		"air",
+		"stone",
+		"grass",
+		"dirt",
+		"cobblestone",
+		"planks",
+		"sapling",
+		"bedrock",
+		"flowing_water",
+		"water",
+
+		"flowing_lava",
+		"lava",
+		"sand",
+		"gravel",
+		"gold_ore",
+		"iron_ore",
+		"coal_ore",
+		"log",
+		"leaves",
+		"sponge",
+
+		"glass",
+		"lapis_ore",
+		"lapis_block",
+		"dispenser",
+		"sandstone",
+		"noteblock",
+		"bed",
+		"golden_rail",
+		"detector_rail",
+		"sticky_piston",
+
+		"web",
+		"tallgrass",
+		"deadbush",
+		"piston",
+		"piston_head",
+		"wool",
+		"piston_extension",
+		"yellow_flower",
+		"red_flower",
+		"brown_mushroom",
+
+		"red_mushroom",
+		"gold_block",
+		"iron_block",
+		"double_stone_slab",
+		"stone_slab",
+		"brick_block",
+		"tnt",
+		"bookshelf",
+		"mossy_cobblestone",
+		"obsidian",
+
+		"torch",
+		"fire",
+		"mob_spawner",
+		"oak_stairs",
+		"chest",
+		"redstone_wire",
+		"diamond_ore",
+		"diamond_block",
+		"crafting_table",
+		"wheat",
+
+		"farmland",
+		"furnace",
+		"lit_furnace",
+		"standing_sign",
+		"wooden_door",
+		"ladder",
+		"rail",
+		"stone_stairs",
+		"wall_sign",
+		"lever",
+
+		"stone_pressure_plate",
+		"iron_door",
+		"wooden_pressure_plate",
+		"redstone_ore",
+		"lit_redstone_ore",
+		"unlit_redstone_torch",
+		"redstone_torch",
+		"stone_button",
+		"snow_layer",
+		"ice",
+
+		"snow",
+		"cactus",
+		"clay",
+		"reeds",
+		"jukebox",
+		"fence",
+		"pumpkin",
+		"netherrack",
+		"soul_sand",
+		"glowstone",
+
+		"portal",
+		"lit_pumpkin",
+		"cake",
+		"unpowered_repeater",
+		"powered_repeater",
+		"april_fools_locked_chest",
+		"trapdoor",
+		"monster_egg",
+		"stonebrick",
+		"brown_mushroom_block",
+
+		"red_mushroom_block",
+		"iron_bars",
+		"glass_pane",
+		"melon_block",
+		"pumpkin_stem",
+		"melon_stem",
+		"vine",
+		"fence_gate",
+		"brick_stairs",
+		"stone_brick_stairs",
+
+		"mycelium",
+		"waterlily",
+		"nether_brick",
+		"nether_brick_fence",
+		"nether_brick_stairs",
+		"nether_wart",
+		"enchanting_table",
+		"brewing_stand",
+		"cauldron",
+		"end_portal",
+
+		"end_portal_frame",
+		"end_stone",
+		"dragon_egg",
+		"redstone_lamp",
+		"lit_redstone_lamp",
+		"double_wooden_slab",
+		"wooden_slab",
+		"cocoa",
+		"sandstone_stairs",
+		"emerald_ore",
+
+		"ender_chest",
+		"tripwire_hook",
+		"tripwire",
+		"emerald_block",
+		"spruce_stairs",
+		"birch_stairs",
+		"jungle_stairs",
+		"command_block",
+		"beacon",
+		"cobblestone_wall",
+
+		"flower_pot",
+		"carrots",
+		"potatoes",
+		"wooden_button",
+		"skull",
+		"anvil",
+		"trapped_chest",
+		"light_weighted_pressure_plate",
+		"heavey_weighted_pressure_plate",
+		"unpowered_comparator",
+
+		"powered_comparator",
+		"daylight_detector",
+		"redstone_block",
+		"quartz_ore",
+		"hopper",
+		"quartz_block",
+		"quartz_stairs",
+		"activator_rail",
+		"dropper",
+		"stained_hardened_clay",
+
+//		IDs 160 to 169 were unused
+		null,
+		null,
+		null,
+		null,
+		null,
+		null,
+		null,
+		null,
+		null,
+		null,
+
+		"hay",
+		"carpet",
+		"hardened_clay",
+		"coal_block"
+	};
+
+	static void init() {
+		// Air block added by OSL
+		register(Blocks.AIR);
+
+		for (Field f : Block.class.getDeclaredFields()) {
+			if (Modifier.isStatic(f.getModifiers()) && Block.class.isAssignableFrom(f.getType())) {
+				try {
+					Block block = (Block) f.get(null);
+
+					if (block != null) {
+						register(block);
+					}
+				} catch (Throwable t) {
+				}
+			}
+		}
+	}
+
+	private static void register(Block block) {
+		if (block.id >= 0 && block.id < IDENTIFIERS.length) {
+			String identifier = IDENTIFIERS[block.id];
+
+			if (identifier != null) {
+				BlockRegistryImpl.register(block.id, NamespacedIdentifiers.from(identifier), block);
+			}
+		}
+	}
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/block/AirBlock.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/block/AirBlock.java
new file mode 100644
index 00000000..1aed2f62
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/block/AirBlock.java
@@ -0,0 +1,38 @@
+package net.ornithemc.osl.blocks.impl.block;
+
+import net.minecraft.block.Block;
+import net.minecraft.block.material.Material;
+import net.minecraft.util.math.Box;
+import net.minecraft.world.World;
+
+public class AirBlock extends Block {
+
+	public AirBlock() {
+		super(0, Material.AIR);
+	}
+
+	@Override
+	public boolean isAir() {
+		return true;
+	}
+
+	@Override
+	public int getRenderType() {
+		return -1;
+	}
+
+	@Override
+	public Box getCollisionShape(World world, int x, int y, int z) {
+		return null;
+	}
+
+	@Override
+	public boolean isSolidRender() {
+		return false;
+	}
+
+	@Override
+	public boolean canRayTrace(int metadata, boolean allowLiquids) {
+		return false;
+	}
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/block/BlockExtensionImpl.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/block/BlockExtensionImpl.java
new file mode 100644
index 00000000..a34f0259
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/block/BlockExtensionImpl.java
@@ -0,0 +1,18 @@
+package net.ornithemc.osl.blocks.impl.block;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.api.block.BlockExtension;
+
+public interface BlockExtensionImpl extends BlockExtension {
+
+	@Override
+	default boolean isAir() {
+		throw new AbstractMethodError();
+	}
+
+	@Override
+	default boolean is(Block block) {
+		throw new AbstractMethodError();
+	}
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java
new file mode 100644
index 00000000..9a9de523
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixin.java
@@ -0,0 +1,52 @@
+package net.ornithemc.osl.blocks.impl.mixin.common;
+
+import org.objectweb.asm.Opcodes;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.Slice;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.impl.BlockRegistryImpl;
+
+@Mixin(Block.class)
+public class BlockMixin {
+
+	@Inject(
+		method = "<clinit>",
+		at = @At(
+			value = "HEAD"
+		)
+	)
+	private static void osl$blocks$unlockBlockRegistry(CallbackInfo ci) {
+		BlockRegistryImpl.unlock();
+	}
+
+	@Inject(
+		method = "<clinit>",
+		slice = @Slice(
+			from = @At(
+				value = "FIELD",
+				opcode = Opcodes.PUTSTATIC,
+				target = "Lnet/minecraft/block/Block;STONE:Lnet/minecraft/block/Block;"
+			)
+		),
+		at = @At(
+			value = "CONSTANT",
+			args = "intValue=256",
+			ordinal = 0
+		)
+	)
+	private static void osl$blocks$initAndLockBlockRegistry(CallbackInfo ci) {
+		BlockRegistryImpl.init();
+		BlockRegistryImpl.lock();
+	}
+
+	@Override
+	public String toString() {
+		return "Block{" + BlockRegistryImpl.getKey((Block) (Object) this) + "}";
+	}
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixinNew.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixinNew.java
new file mode 100644
index 00000000..51098abb
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixinNew.java
@@ -0,0 +1,21 @@
+package net.ornithemc.osl.blocks.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.api.block.BlockExtension;
+
+@Mixin(Block.class)
+public class BlockMixinNew implements BlockExtension {
+
+	@Override
+	public boolean isAir() {
+		return false;
+	}
+
+	@Override
+	public boolean is(Block block) {
+		return ((Block) (Object) this).is(block.id);
+	}
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixinOld.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixinOld.java
new file mode 100644
index 00000000..15a537b7
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/BlockMixinOld.java
@@ -0,0 +1,21 @@
+package net.ornithemc.osl.blocks.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+
+import net.minecraft.block.Block;
+
+import net.ornithemc.osl.blocks.api.block.BlockExtension;
+
+@Mixin(Block.class)
+public class BlockMixinOld implements BlockExtension {
+
+	@Override
+	public boolean isAir() {
+		return false;
+	}
+
+	@Override
+	public boolean is(Block block) {
+		return (Block) (Object) this == block;
+	}
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/RedstoneTorchBlockMixin.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/RedstoneTorchBlockMixin.java
new file mode 100644
index 00000000..2339ee23
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/RedstoneTorchBlockMixin.java
@@ -0,0 +1,21 @@
+package net.ornithemc.osl.blocks.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+
+import net.minecraft.block.Block;
+import net.minecraft.block.RedstoneTorchBlock;
+import net.minecraft.block.material.Material;
+
+@Mixin(RedstoneTorchBlock.class)
+public class RedstoneTorchBlockMixin extends Block {
+
+	private RedstoneTorchBlockMixin(int id, Material material) {
+		super(id, material);
+	}
+
+	@Override
+	public boolean is(Block block) {
+		return block == Block.REDSTONE_TORCH || block == Block.UNLIT_REDSTONE_TORCH;
+	}
+
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/RepeaterBlockMixin.java b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/RepeaterBlockMixin.java
new file mode 100644
index 00000000..8ffde7e8
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/java/net/ornithemc/osl/blocks/impl/mixin/common/RepeaterBlockMixin.java
@@ -0,0 +1,21 @@
+package net.ornithemc.osl.blocks.impl.mixin.common;
+
+import org.spongepowered.asm.mixin.Mixin;
+
+import net.minecraft.block.Block;
+import net.minecraft.block.RepeaterBlock;
+import net.minecraft.block.material.Material;
+
+@Mixin(RepeaterBlock.class)
+public class RepeaterBlockMixin extends Block {
+
+	private RepeaterBlockMixin(int id, Material material) {
+		super(id, material);
+	}
+
+	@Override
+	public boolean is(Block block) {
+		return block == Block.REPEATER || block == Block.POWERED_REPEATER;
+	}
+
+}
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/resources/fabric.mod.json b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..beee7d68
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/resources/fabric.mod.json
@@ -0,0 +1,26 @@
+{
+  "schemaVersion": 1,
+  "id": "osl-blocks",
+  "version": "0.1.0-alpha.1+mca1.0.1_01-mc1.6.4",
+  "environment": "*",
+  "mixins": [
+    "osl.blocks.mixins.json"
+  ],
+  "accessWidener": "osl.blocks.classtweaker",
+  "depends": {
+    "fabricloader": "\u003e\u003d0.18.0",
+    "minecraft": "\u003e\u003d1.0.0-alpha.0.1 \u003c\u003d1.6.4",
+    "osl-core": "\u003e\u003d0.7.0"
+  },
+  "name": "OSL Blocks",
+  "description": "Blocks API and events.",
+  "authors": [
+    "OrnitheMC"
+  ],
+  "contact": {
+    "homepage": "https://ornithemc.net/",
+    "issues": "https://github.com/OrnitheMC/ornithe-standard-libraries/issues",
+    "sources": "https://github.com/OrnitheMC/ornithe-standard-libraries"
+  },
+  "license": "Apache-2.0"
+}
\ No newline at end of file
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/resources/osl.blocks.classtweaker b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/resources/osl.blocks.classtweaker
new file mode 100644
index 00000000..d4ae7c59
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/resources/osl.blocks.classtweaker
@@ -0,0 +1,14 @@
+classTweaker	v1	named
+
+transitive-accessible	method	net/minecraft/block/Block	setSounds	(Lnet/minecraft/block/Block$Sounds;)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setOpacity	(I)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setLight	(F)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setBlastResistance	(F)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setStrength	(F)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setUnbreakable	()Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setTicksRandomly	(Z)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setKey	(Ljava/lang/String;)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setCreativeModeTab	(Lnet/minecraft/item/CreativeModeTab;)Lnet/minecraft/block/Block;
+transitive-accessible	method	net/minecraft/block/Block	setSpriteName	(Ljava/lang/String;)Lnet/minecraft/block/Block;
+
+transitive-inject-interface	net/minecraft/block/Block	net/ornithemc/osl/blocks/impl/block/BlockExtensionImpl
\ No newline at end of file
diff --git a/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/resources/osl.blocks.mixins.json b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/resources/osl.blocks.mixins.json
new file mode 100644
index 00000000..c3640215
--- /dev/null
+++ b/libraries/blocks/blocks-mca1.0.1_01-mc1.6.4/src/main/resources/osl.blocks.mixins.json
@@ -0,0 +1,21 @@
+{
+	"required": true,
+	"minVersion": "0.8",
+	"package": "net.ornithemc.osl.blocks.impl.mixin",
+	"compatibilityLevel": "JAVA_8",
+	"plugin": "net.ornithemc.osl.blocks.impl.BlocksMixinPlugin",
+	"mixins": [
+		"common.BlockMixin",
+		"common.BlockMixinNew",
+		"common.BlockMixinOld",
+		"common.RedstoneTorchBlockMixin",
+		"common.RepeaterBlockMixin"
+	],
+	"client": [
+	],
+	"server": [
+	],
+	"injectors": {
+		"defaultRequire": 1
+	}
+}
diff --git a/libraries/blocks/build.gradle b/libraries/blocks/build.gradle
new file mode 100644
index 00000000..e98ba2c6
--- /dev/null
+++ b/libraries/blocks/build.gradle
@@ -0,0 +1 @@
+setUpLibrary(project)
diff --git a/libraries/blocks/gradle.properties b/libraries/blocks/gradle.properties
new file mode 100644
index 00000000..12b27d8f
--- /dev/null
+++ b/libraries/blocks/gradle.properties
@@ -0,0 +1,6 @@
+library_id = blocks
+library_name = Blocks
+library_description = Blocks API and events.
+library_version = 0.1.0-alpha.1
+
+osl_dependencies = core:>=0.7.0
diff --git a/libraries/core/src/main/java/net/ornithemc/osl/core/api/registry/SimpleIdRegistry.java b/libraries/core/src/main/java/net/ornithemc/osl/core/api/registry/SimpleIdRegistry.java
new file mode 100644
index 00000000..eb42caf8
--- /dev/null
+++ b/libraries/core/src/main/java/net/ornithemc/osl/core/api/registry/SimpleIdRegistry.java
@@ -0,0 +1,84 @@
+package net.ornithemc.osl.core.api.registry;
+
+import java.util.HashMap;
+import java.util.IdentityHashMap;
+import java.util.Map;
+import java.util.Set;
+
+import it.unimi.dsi.fastutil.ints.Int2ReferenceMap;
+import it.unimi.dsi.fastutil.ints.Int2ReferenceOpenHashMap;
+import it.unimi.dsi.fastutil.objects.Reference2IntMap;
+import it.unimi.dsi.fastutil.objects.Reference2IntOpenHashMap;
+
+import net.ornithemc.osl.core.api.util.NamespacedIdentifier;
+
+public final class SimpleIdRegistry<T> {
+
+	private final Int2ReferenceMap<T> values;
+	private final Reference2IntMap<T> ids;
+	private final Map<NamespacedIdentifier, T> registry;
+	private final Map<T, NamespacedIdentifier> keys;
+
+	private int nextId = 0;
+
+	public SimpleIdRegistry() {
+		this.values = new Int2ReferenceOpenHashMap<>();
+		this.ids = new Reference2IntOpenHashMap<>();
+		this.registry = new HashMap<>();
+		this.keys = new IdentityHashMap<>();
+
+		this.ids.defaultReturnValue(-1);
+	}
+
+	public T register(NamespacedIdentifier key, T value) {
+		return this.register(this.nextId++, key, value);
+	}
+
+	public T register(int id, NamespacedIdentifier key, T value) {
+		if (id < 0) {
+			throw new IllegalStateException("invalid ID " + id + " (must be >= 0)");
+		}
+		if (this.values.containsKey(id)) {
+			throw new IllegalStateException("duplicate ID " + id + " (" + this.getKey(this.get(id)) + " and " + key + ")");
+		}
+		if (this.registry.containsKey(key)) {
+			throw new IllegalStateException("duplicate Namespaced ID " + key + " (" + this.getId(this.get(key)) + " and " + id + ")");
+		}
+		if (this.ids.containsKey(value) || this.keys.containsKey(value)) {
+			throw new IllegalStateException("value registered twice (" + this.getId(value) + ", " + this.getKey(value) + " and " + id + ", " + key + ")");
+		}
+
+		this.values.put(id, value);
+		this.ids.put(value, id);
+		this.registry.put(key, value);
+		this.keys.put(value, key);
+
+		this.nextId = Math.max(this.nextId, id + 1);
+
+		return value;
+	}
+
+	public T get(int id) {
+		return this.values.get(id);
+	}
+
+	public T get(NamespacedIdentifier key) {
+		return this.registry.get(key);
+	}
+
+	public boolean has(T value) {
+		return this.ids.containsKey(value);
+	}
+
+	public int getId(T value) {
+		return this.ids.getInt(value);
+	}
+
+	public NamespacedIdentifier getKey(T value) {
+		return this.keys.get(value);
+	}
+
+	public Set<NamespacedIdentifier> keySet() {
+		return this.registry.keySet();
+	}
+}
diff --git a/settings.gradle b/settings.gradle
index 3fcddc03..528fd073 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -22,6 +22,14 @@ include ':libraries:core'
 include ':libraries:core:core-mca1.0.1_01-mc14w26c'
 include ':libraries:core:core-mc14w27a-mc1.14.4'
 
+include ':libraries:blocks'
+include ':libraries:blocks:blocks-mca1.0.1_01-mc1.6.4'
+include ':libraries:blocks:blocks-mc13w36a-mc14w26c'
+include ':libraries:blocks:blocks-mc14w27a-mc17w46a'
+include ':libraries:blocks:blocks-mc17w47a-mc18w31a'
+include ':libraries:blocks:blocks-mc18w32a-mc1.13.2'
+include ':libraries:blocks:blocks-mc18w43a-mc1.14.4'
+
 include ':libraries:branding'
 include ':libraries:branding:branding-mcin-20100206-2103-mca1.2.1_01'
 include ':libraries:branding:branding-mca1.2.2-mc14w29b'