diff --git a/jdm-core/src/main/java/jdiskmark/App.java b/jdm-core/src/main/java/jdiskmark/App.java
index be290d5..440c8ee 100644
--- a/jdm-core/src/main/java/jdiskmark/App.java
+++ b/jdm-core/src/main/java/jdiskmark/App.java
@@ -1,9 +1,5 @@
 package jdiskmark;
 
-import static jdiskmark.Benchmark.BenchmarkType;
-import static jdiskmark.Benchmark.BlockSequence;
-import static jdiskmark.Benchmark.IOMode.READ;
-import static jdiskmark.Benchmark.IOMode.WRITE;
 import static jdiskmark.DriveAccessChecker.validateTargetDirectory;
 
 import picocli.CommandLine;
@@ -109,6 +105,50 @@ public String toString() {
         }
     }
 
+    /**
+     * Branding icon variants for the application window, taskbar, and installer.
+     * Change {@link #activeIcon} to switch the icon across all display contexts.
+     */
+    public enum AppIcon {
+        BETA("/icons/icon-jdm-beta.png"),
+        /** Custom JDiskMark turtle logo — the default project brand. */
+        TURTLE("/icons/icon-jdm-turtle.png"),
+        /** Duke, the BSD-licensed Java mascot from the OpenJDK project. */
+        DUKE("/icons/icon-duke.png");
+
+        public final String resourcePath;
+
+        AppIcon(String resourcePath) {
+            this.resourcePath = resourcePath;
+        }
+
+        /**
+         * Load this icon as an ImageIcon, or {@code null} if the resource
+         * is not found on the classpath.
+         */
+        public javax.swing.ImageIcon load() {
+            java.io.InputStream is = App.class.getResourceAsStream(resourcePath);
+            if (is == null) {
+                java.util.logging.Logger.getLogger(App.class.getName()).warning(
+                        "Icon resource not found: " + resourcePath);
+                return null;
+            }
+            try (is) {
+                return new javax.swing.ImageIcon(is.readAllBytes());
+            } catch (java.io.IOException e) {
+                java.util.logging.Logger.getLogger(App.class.getName()).log(
+                        java.util.logging.Level.WARNING, "Could not load icon: " + resourcePath, e);
+                return null;
+            }
+        }
+    }
+
+    /**
+     * Active branding icon — change this single line to switch the icon
+     * used for the window title bar, taskbar, and About dialog.
+     */
+    public static AppIcon activeIcon = AppIcon.TURTLE;
+
     // application mode
     public static Mode mode = Mode.CLI;
     // elevated priviledges
diff --git a/jdm-core/src/main/java/jdiskmark/Gui.java b/jdm-core/src/main/java/jdiskmark/Gui.java
index 1646a0b..e647f37 100644
--- a/jdm-core/src/main/java/jdiskmark/Gui.java
+++ b/jdm-core/src/main/java/jdiskmark/Gui.java
@@ -109,6 +109,9 @@ public static void configureDarkLaf() {
             } else if (App.os.contains("Linux")) {
                 UIManager.setLookAndFeel(new FlatDarkLaf());
             }
+            // Enable FlatLaf custom window decorations (unified title bar + menu bar)
+            javax.swing.JFrame.setDefaultLookAndFeelDecorated(true);
+            javax.swing.JDialog.setDefaultLookAndFeelDecorated(true);
         } catch (UnsupportedLookAndFeelException e) {
             //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
             /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
@@ -126,6 +129,8 @@ public static void configureDarkLaf() {
     public static void configureDarculaLaf() {
         try {
             UIManager.setLookAndFeel(new FlatDarculaLaf());
+            javax.swing.JFrame.setDefaultLookAndFeelDecorated(true);
+            javax.swing.JDialog.setDefaultLookAndFeelDecorated(true);
         } catch (UnsupportedLookAndFeelException e) {
             //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
             /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
@@ -149,6 +154,8 @@ public static void configureLightLaf() {
             } else if (App.os.contains("Linux")) {
                 UIManager.setLookAndFeel(new FlatLightLaf());
             }
+            javax.swing.JFrame.setDefaultLookAndFeelDecorated(true);
+            javax.swing.JDialog.setDefaultLookAndFeelDecorated(true);
         } catch (UnsupportedLookAndFeelException e) {
             //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
             /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
@@ -228,6 +235,17 @@ public static void init() {
         }
         
         mainFrame = new MainFrame();
+
+        // Embed the menu bar into the FlatLaf custom title bar (VS Code style)
+        mainFrame.getRootPane().putClientProperty(
+                com.formdev.flatlaf.FlatClientProperties.MENU_BAR_EMBEDDED, true);
+
+        // Apply branding icon to the window title bar and taskbar
+        javax.swing.ImageIcon icon = App.activeIcon.load();
+        if (icon != null) {
+            mainFrame.setIconImage(icon.getImage());
+        }
+
         if (runPanel != null) {
             runPanel.hideFirstColumn();
         }
diff --git a/jdm-core/src/main/java/jdiskmark/MainFrame.java b/jdm-core/src/main/java/jdiskmark/MainFrame.java
index e0dcfef..08e30b6 100644
--- a/jdm-core/src/main/java/jdiskmark/MainFrame.java
+++ b/jdm-core/src/main/java/jdiskmark/MainFrame.java
@@ -839,8 +839,17 @@ private void exitMenuItemActionPerformed(java.awt.event.ActionEvent evt) {//GEN-
     }//GEN-LAST:event_exitMenuItemActionPerformed
 
     private void aboutMenuItemActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_aboutMenuItemActionPerformed
-        JOptionPane.showMessageDialog(Gui.mainFrame, 
-                "JDiskMark " + App.VERSION, "About...", JOptionPane.PLAIN_MESSAGE);
+        javax.swing.ImageIcon rawIcon = App.activeIcon.load();
+        javax.swing.ImageIcon icon = rawIcon;
+        if (rawIcon != null) {
+            int w = rawIcon.getIconWidth() / 2;
+            int h = rawIcon.getIconHeight() / 2;
+            java.awt.Image scaled = rawIcon.getImage()
+                    .getScaledInstance(w, h, java.awt.Image.SCALE_SMOOTH);
+            icon = new javax.swing.ImageIcon(scaled);
+        }
+        JOptionPane.showMessageDialog(Gui.mainFrame,
+                "JDiskMark " + App.VERSION, "About...", JOptionPane.PLAIN_MESSAGE, icon);
     }//GEN-LAST:event_aboutMenuItemActionPerformed
 
     private void openLocButtonActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_openLocButtonActionPerformed
diff --git a/jdm-core/src/main/resources/icons/icon-duke.png b/jdm-core/src/main/resources/icons/icon-duke.png
new file mode 100644
index 0000000..62b6b5c
Binary files /dev/null and b/jdm-core/src/main/resources/icons/icon-duke.png differ
diff --git a/jdm-core/src/main/resources/icons/icon-jdm-beta.png b/jdm-core/src/main/resources/icons/icon-jdm-beta.png
new file mode 100644
index 0000000..4417127
Binary files /dev/null and b/jdm-core/src/main/resources/icons/icon-jdm-beta.png differ
diff --git a/jdm-core/src/main/resources/icons/icon-jdm-turtle-bw.png b/jdm-core/src/main/resources/icons/icon-jdm-turtle-bw.png
new file mode 100644
index 0000000..edf9bdb
Binary files /dev/null and b/jdm-core/src/main/resources/icons/icon-jdm-turtle-bw.png differ
diff --git a/jdm-core/src/main/resources/icons/icon-jdm-turtle.png b/jdm-core/src/main/resources/icons/icon-jdm-turtle.png
new file mode 100644
index 0000000..05a7453
Binary files /dev/null and b/jdm-core/src/main/resources/icons/icon-jdm-turtle.png differ
diff --git a/jdm-core/src/test/java/jdiskmark/AppTest.java b/jdm-core/src/test/java/jdiskmark/AppTest.java
index 734bcc5..7472799 100644
--- a/jdm-core/src/test/java/jdiskmark/AppTest.java
+++ b/jdm-core/src/test/java/jdiskmark/AppTest.java
@@ -1,6 +1,8 @@
 package jdiskmark;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
 import static org.junit.jupiter.api.Assertions.*;
 
 /**
@@ -23,4 +25,16 @@ void sharePortal_onStartup_isFalse() {
         assertFalse(App.sharePortal,
                 "sharePortal must default to false — network activity requires explicit user opt-in each session");
     }
+
+    /**
+     * Every AppIcon enum entry must resolve to an actual classpath resource.
+     * This guards against icon renames or path typos that would cause the
+     * About dialog (and taskbar/title-bar) to silently display no icon.
+     */
+    @ParameterizedTest
+    @EnumSource(App.AppIcon.class)
+    void appIcon_load_isNonNull(App.AppIcon icon) {
+        assertNotNull(icon.load(),
+                "Icon resource not found on classpath: " + icon.resourcePath);
+    }
 }
diff --git a/jdm-dist/jdm-deb-slim/pom.xml b/jdm-dist/jdm-deb-slim/pom.xml
index bc2ceeb..e1dbed9 100644
--- a/jdm-dist/jdm-deb-slim/pom.xml
+++ b/jdm-dist/jdm-deb-slim/pom.xml
@@ -101,6 +101,30 @@
                                                 <group>root</group>
                                             </mapper>
                                         </data>
+                                        <!-- App icon — installed to /usr/share/pixmaps for XDG icon resolution -->
+                                        <data>
+                                            <src>${project.basedir}/../../jdm-core/src/main/resources/icons/icon-jdm-turtle.png</src>
+                                            <type>file</type>
+                                            <dst>/usr/share/pixmaps/jdiskmark.png</dst>
+                                            <mapper>
+                                                <type>perm</type>
+                                                <filemode>644</filemode>
+                                                <user>root</user>
+                                                <group>root</group>
+                                            </mapper>
+                                        </data>
+                                        <!-- Desktop entry — includes Icon= and StartupWMClass for GNOME taskbar -->
+                                        <data>
+                                            <src>${project.basedir}/src/deb/share/jdiskmark.desktop</src>
+                                            <type>file</type>
+                                            <mapper>
+                                                <type>perm</type>
+                                                <prefix>/usr/share/applications</prefix>
+                                                <filemode>644</filemode>
+                                                <user>root</user>
+                                                <group>root</group>
+                                            </mapper>
+                                        </data>
                                     </dataSet>
                                 </configuration>
                             </execution>
diff --git a/jdm-dist/jdm-deb-slim/src/deb/share/jdiskmark.desktop b/jdm-dist/jdm-deb-slim/src/deb/share/jdiskmark.desktop
new file mode 100644
index 0000000..ba5508c
--- /dev/null
+++ b/jdm-dist/jdm-deb-slim/src/deb/share/jdiskmark.desktop
@@ -0,0 +1,12 @@
+[Desktop Entry]
+Type=Application
+Version=1.0
+Name=JDiskMark
+GenericName=Disk Benchmark
+Comment=Java disk benchmark utility for read/write performance testing
+Exec=/usr/bin/jdiskmark
+Icon=jdiskmark
+Terminal=false
+Categories=Utility;System;
+Keywords=disk;benchmark;performance;storage;speed;
+StartupWMClass=jdiskmark-App
diff --git a/jdm-dist/jdm-deb/pom.xml b/jdm-dist/jdm-deb/pom.xml
index 30baf26..e0bc247 100644
--- a/jdm-dist/jdm-deb/pom.xml
+++ b/jdm-dist/jdm-deb/pom.xml
@@ -50,9 +50,55 @@
                                         <argument>--java-options</argument><argument>${jvm.run.options}</argument>
                                         <argument>--linux-shortcut</argument>
                                         <argument>--linux-menu-group</argument><argument>Utility</argument>
+                                        <argument>--icon</argument><argument>${project.basedir}/../../jdm-core/src/main/resources/icons/icon-jdm-turtle.png</argument>
+                                        <argument>--resource-dir</argument><argument>${project.basedir}/src/main/jpackage-resources</argument>
                                     </arguments>
                                 </configuration>
                             </execution>
+
+                            <!-- Inject fields that jpackage does not generate into the desktop
+                                 entry inside the DEB: Name=JDiskMark (display name),
+                                 StartupWMClass (for GNOME taskbar icon matching),
+                                 GenericName, and Keywords.
+                                 The file is patched in-place; no renaming is done so that
+                                 xdg-desktop-menu's vendor-prefix requirement is satisfied. -->
+                            <execution>
+                                <id>patch-deb-desktop</id>
+                                <phase>verify</phase>
+                                <goals>
+                                    <goal>exec</goal>
+                                </goals>
+                                <configuration>
+                                    <executable>bash</executable>
+                                    <arguments>
+                                        <argument>-c</argument>
+                                        <argument><![CDATA[
+set -e
+mapfile -t DEBS < <(find "${project.build.directory}" -maxdepth 1 -type f -name "*.deb" | sort)
+if [ "${#DEBS[@]}" -ne 1 ]; then
+    echo "[patch] Expected exactly one .deb in ${project.build.directory}, found ${#DEBS[@]}" >&2
+    printf '  %s\n' "${DEBS[@]}" >&2
+    exit 1
+fi
+DEB="${DEBS[0]}"
+WORK="${project.build.directory}/deb-repack"
+echo "[patch] Patching desktop entry in $DEB"
+rm -rf "$WORK" && mkdir -p "$WORK/pkg"
+dpkg-deb -R "$DEB" "$WORK/pkg"
+DESKTOP=$(find "$WORK/pkg/opt" -name "*.desktop" | grep -v runtime | head -1)
+if [ -n "$DESKTOP" ]; then
+    sed -i 's|^Name=jdiskmark$|Name=JDiskMark|' "$DESKTOP"
+    sed -i 's|^Categories=\(.*\)|GenericName=Disk Benchmark\nCategories=\1\nKeywords=disk;benchmark;performance;storage;speed;\nStartupWMClass=jdiskmark-App|' "$DESKTOP"
+    echo "[patch] Result ($(basename $DESKTOP)):"
+    cat "$DESKTOP"
+fi
+dpkg-deb -b "$WORK/pkg" "$DEB"
+echo "[patch] Done."
+                                        ]]></argument>
+                                    </arguments>
+                                </configuration>
+                            </execution>
+
                         </executions>
                     </plugin>
                 </plugins>
diff --git a/jdm-dist/jdm-deb/src/main/jpackage-resources/template.desktop b/jdm-dist/jdm-deb/src/main/jpackage-resources/template.desktop
new file mode 100644
index 0000000..d37986a
--- /dev/null
+++ b/jdm-dist/jdm-deb/src/main/jpackage-resources/template.desktop
@@ -0,0 +1,12 @@
+[Desktop Entry]
+Name=APPLICATION_NAME
+GenericName=Disk Benchmark
+Comment=APPLICATION_DESCRIPTION
+Exec=APPLICATION_LAUNCHER
+Icon=APPLICATION_ICON
+Terminal=false
+Type=Application
+Categories=DEPLOY_BUNDLE_CATEGORY
+Keywords=disk;benchmark;performance;storage;speed;
+StartupWMClass=jdiskmark-App
+DESKTOP_MIMES
diff --git a/jdm-dist/jdm-deb/src/main/jpackage-resources/template.postinst b/jdm-dist/jdm-deb/src/main/jpackage-resources/template.postinst
new file mode 100644
index 0000000..c5e2e40
--- /dev/null
+++ b/jdm-dist/jdm-deb/src/main/jpackage-resources/template.postinst
@@ -0,0 +1,38 @@
+#!/bin/sh
+# postinst script for APPLICATION_PACKAGE
+#
+# see: dh_installdeb(1)
+
+set -e
+
+# summary of how this script can be called:
+#        * <postinst> `configure' <most-recently-configured-version>
+#        * <old-postinst> `abort-upgrade' <new version>
+#        * <conflictor's-postinst> `abort-remove' `in-favour' <package>
+#          <new-version>
+#        * <postinst> `abort-remove'
+#        * <deconfigured's-postinst> `abort-configure' `in-favour'
+#          <failed-install-package> <version> `removing'
+#          <conflicting-package> <version>
+# for details, see https://www.debian.org/doc/debian-policy/ or
+# the debian-policy package
+
+package_type=deb
+LAUNCHER_AS_SERVICE_SCRIPTS
+
+case "$1" in
+    configure)
+DESKTOP_COMMANDS_INSTALL
+LAUNCHER_AS_SERVICE_COMMANDS_INSTALL
+    ;;
+
+    abort-upgrade|abort-remove|abort-deconfigure)
+    ;;
+
+    *)
+        echo "postinst called with unknown argument \`$1'" >&2
+        exit 1
+    ;;
+esac
+
+exit 0