diff --git a/CLAUDE.md b/CLAUDE.md
index 6546a31..c9c35b6 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -13,11 +13,11 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 ## Overview
 
-RDFa-Editor is a prototype XHTML+RDFa authoring tool using client-side XSLT. Content lives in a `#content` container of structured blocks (p, h1–h3, ul/ol, blockquote, pre, figure, table), always editable Notion-style: typing within blocks, Enter splits, Backspace-at-start merges, toolbar for block types / inline formatting / lists / figures / tables / links, drag-handle reordering (nested blocks included — every `%block` drags, drops land wherever the content model admits it), a `/` slash menu (in an empty block) and markdown shortcuts (`# `, `- `, `1. `, `> `, ` ``` `) that insert/convert blocks per the content model. Nesting follows the **XHTML Strict content model** (see content-model.xsl below): `blockquote` is a block *container* (`blockquote > p+` — bare text inside it is invalid and gets normalized; the toolbar quote toggle wraps/unwraps), `li`/`td`/`th`/`dd`/`figcaption` are `%Flow;` (mixed text AND nested blocks — Tab/Shift+Tab indent/outdent nested lists), `p`/`h1–h6`/`caption`/`dt` are inline-only. Tables are composite blocks (structure locked; `td`/`th`/`caption` editable) inserted via a rows×cols dialog with an optional header row and caption; row/column toolbar controls, Tab/Shift+Tab cell traversal and Enter (step down a column) all grow the grid at its bottom edge. Right-click a text selection to annotate it with RDFa; right-click an existing annotation to edit or remove it. "Extract RDF" shows the page's triples; "Source" shows the canonical XHTML+RDFa serialization (all editing ephemera stripped).
+RDFa-Editor is a prototype XHTML+RDFa authoring tool using client-side XSLT. Content lives in a `#content` container of structured blocks (p, h1–h3, ul/ol, blockquote, pre, figure, table), always editable Notion-style: typing within blocks, Enter splits, Backspace-at-start merges, toolbar for block types / inline formatting / lists / figures / tables / links, drag-handle reordering (nested blocks included — every `%block` drags, drops land wherever the content model admits it), a `/` slash menu (in an empty block) and markdown shortcuts (`# `, `- `, `1. `, `> `, ` ``` `) that insert/convert blocks per the content model. Nesting follows the **XHTML Strict content model** (see content-model.xsl below): `blockquote` is a block *container* (`blockquote > p+` — bare text inside it is invalid and gets normalized; the toolbar quote toggle wraps/unwraps), `li`/`td`/`th`/`dd`/`figcaption` are `%Flow;` (mixed text AND nested blocks — Tab/Shift+Tab indent/outdent nested lists), `p`/`h1–h6`/`caption`/`dt` are inline-only. Tables are composite blocks (structure locked; `td`/`th`/`caption` editable) inserted via a rows×cols dialog with an optional header row and caption; row/column toolbar controls, Tab/Shift+Tab cell traversal and Enter (step down a column) all grow the grid at its bottom edge. Right-click a text selection to annotate it with RDFa; right-click an existing annotation to edit or remove it. "Extract RDF" shows the page's triples; "Source" shows the canonical XHTML+RDFa serialization (all editing ephemera stripped) in [Exclusive XML Canonicalization](https://www.w3.org/TR/xml-exc-c14n/) form (`<br></br>`, sorted attributes/namespace declarations, no indentation — the `rdf:XMLLiteral` value space).
 
 ## Architecture
 
-XSLT 3.0 running on **SaxonJS 3** with its interactive extensions (`ixsl:` namespace). `index.html` loads `lib/SaxonJS3.js` and executes `dist/index.xsl.sef.json` (initial template `main`). The editor UI is fully generated by the stylesheet — the overlay is rendered once at startup (hidden) and only populated/shown/hidden afterwards, so the stylesheet is self-contained and embeddable on any host page.
+XSLT 3.0 running on **SaxonJS 3** with its interactive extensions (`ixsl:` namespace). `index.html` loads `lib/SaxonJS3.js` plus `lib/xml-c14n-sync.js` (the exclusive-c14n serializer LinkedDataHub also ships — the "Source" view calls it through `local:canonicalize-xml` in edit.xsl, a port of LDH's `ldh:canonicalize-xml`: `serialize()` → `parse-xml()` bridges XDM to browser DOM, which the lib walks) and executes `dist/index.xsl.sef.json` (initial template `main`). The editor UI is fully generated by the stylesheet — the overlay is rendered once at startup (hidden) and only populated/shown/hidden afterwards, so the stylesheet is self-contained and embeddable on any host page (host pages must include both libs).
 
 Modules under `src/`:
 
diff --git a/README.md b/README.md
index c52c93d..0133983 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,9 @@ RDFa extraction and the document canonicalization are all XSLT.
   vocabulary dropdowns fed by plain ontology RDF/XML files); right-click an annotation
   to edit or remove it.
 - **Strictly W3C-conformant RDFa 1.1 extraction** to RDF/XML ("Extract RDF"), a
-  **canonical serialization** stripping all editing ephemera ("Source"), and
+  **canonical serialization** stripping all editing ephemera and emitting
+  [Exclusive XML Canonicalization](https://www.w3.org/TR/xml-exc-c14n/) — the
+  `rdf:XMLLiteral` value space ("Source"), and
   **RDFa lint** (unresolvable terms, unsafe markup, step-11 conflicts) surfaced as
   wavy underlines + a breadcrumb badge.
 - **Navigation**: ToC drawer (outline with section drag-reorder), breadcrumb bar with
@@ -47,8 +49,10 @@ See `CLAUDE.md` for the module map and conventions. The load-bearing pieces:
 `src/canonical-xhtml.xsl` (canonical + sanitized serialization form, pure XSLT),
 `src/lint-rdfa.xsl` (pure), and the IXSL modules `edit.xsl` / `annotate.xsl` /
 `overlay.xsl` / `navigate.xsl` / `undo.xsl` / `vocab.xsl`. The editor's stylesheet is
-self-contained: a host page provides one or more `.rdfa-editor-content` regions, `rdfa-editor.css`, and
-preloads the vocabulary documents into the SaxonJS document pool (see `index.html`).
+self-contained: a host page provides one or more `.rdfa-editor-content` regions, `rdfa-editor.css`,
+loads `lib/xml-c14n-sync.js` (the exclusive-c14n serializer the "Source" view uses — the same lib
+LinkedDataHub canonicalizes `rdf:XMLLiteral`s with), and preloads the vocabulary documents into the
+SaxonJS document pool (see `index.html`).
 
 ## Embedding in LinkedDataHub
 
diff --git a/index.html b/index.html
index 1de806e..aa8d6f7 100644
--- a/index.html
+++ b/index.html
@@ -6,6 +6,7 @@
 		<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,400,500,700" type="text/css">
         <title>RDFa Editor</title>
 		  <script type="text/javascript" src="lib/SaxonJS3.js"></script>
+		  <script type="text/javascript" src="lib/xml-c14n-sync.js"></script>
 		  <script type="text/javascript">
 				window.onload = function() {
 					// preload the vocabulary documents into the SaxonJS document pool,
diff --git a/lib/xml-c14n-sync.js b/lib/xml-c14n-sync.js
new file mode 100644
index 0000000..d74806a
--- /dev/null
+++ b/lib/xml-c14n-sync.js
@@ -0,0 +1 @@
+(()=>{var e={237:(e,t,n)=>{var r=n(291),i={algorithms:{"http://www.w3.org/2001/10/xml-exc-c14n#":function(e){return new r(e)},"http://www.w3.org/2001/10/xml-exc-c14n#WithComments":function(e){return(e=Object.create(e||null)).includeComments=!0,new r(e)}}},o=e.exports=function e(){if(!(this instanceof e))return new e;this.algorithms=Object.create(i.algorithms)};o.prototype.registerAlgorithm=function(e,t){return this.algorithms[e]=t,this},o.prototype.getAlgorithm=function(e){return this.algorithms[e]},o.prototype.createCanonicaliser=function(e,t){return this.algorithms[e](t)}},936:e=>{var t=e.exports=function(e){};t.prototype.name=function(){return null},t.prototype.canonicalise=function(e,t){setImmediate((function(){return t(Error("not implemented"))}))},t.prototype.canonicaliseSync=function(e){throw Error("not implemented")}},291:(e,t,n)=>{var r=n(418),i=n(936),o=e.exports=function(e){i.call(this,e),e=e||{},this.includeComments=!!e.includeComments,this.inclusiveNamespaces=e.inclusiveNamespaces||[]};o.prototype=Object.create(i.prototype,{constructor:{value:o}}),o.prototype.name=function(){return"http://www.w3.org/2001/10/xml-exc-c14n#"+(this.includeComments?"WithComments":"")},o.prototype.canonicalise=function(e,t){var n=this;setImmediate((function(){try{var r=n._processInner(e)}catch(e){return t(e)}return t(null,r)}))},o.prototype.canonicaliseSync=function(e){return this._processInner(e)},o.prototype.getIncludeComments=function(){return!!this.includeComments},o.prototype.setIncludeComments=function(e){this.includeComments=!!e},o.prototype.getInclusiveNamespaces=function(){return this.inclusiveNamespaces.slice()},o.prototype.setInclusiveNamespaces=function(e){return this.inclusiveNamespaces=e.slice(),this},o.prototype.addInclusiveNamespace=function(e){return this.inclusiveNamespaces.push(e),this};var s=function(e,t){return!e.prefix&&t.prefix?-1:!t.prefix&&e.prefix?1:e.name.localeCompare(t.name)},a=function(e,t){var n=e.prefix+e.namespaceURI,r=t.prefix+t.namespaceURI;return n===r?0:n.localeCompare(r)};o.prototype._renderAttributes=function(e){return(e.attributes?[].slice.call(e.attributes):[]).filter((function(e){return 0!==e.name.indexOf("xmlns")})).sort(s).map((function(e){return" "+e.name+'="'+r.attributeEntities(e.value)+'"'})).join("")},o.prototype._renderNamespace=function(e,t,n){var i="",o=n,s=t.slice(),c=[],u=e.namespaceURI||"";if(e.prefix){if((m=s.filter((function(t){return t.prefix===e.prefix})).shift())&&m.namespaceURI!==e.namespaceURI){for(var p=0;p<s.length;++p)s[p].prefix===e.prefix&&s.splice(p--,1);m=null}m||(c.push({prefix:e.prefix,namespaceURI:e.namespaceURI}),s.push({prefix:e.prefix,namespaceURI:e.namespaceURI}))}else n!==u&&(o=u,i+=' xmlns="'+r.attributeEntities(o)+'"');if(e.attributes)for(p=0;p<e.attributes.length;p++){var l=e.attributes[p],m=null;if(l.prefix&&"xmlns"!==l.prefix&&(m=s.filter((function(e){return e.prefix===l.prefix})).shift())&&m.namespaceURI!==l.namespaceURI){for(p=0;p<s.length;++p)s[p].prefix===l.prefix&&s.splice(p--,1);m=null}l.prefix&&!m&&"xmlns"!==l.prefix?(c.push({prefix:l.prefix,namespaceURI:l.namespaceURI}),s.push({prefix:l.prefix,namespaceURI:l.namespaceURI})):l.prefix&&"xmlns"===l.prefix&&-1!==this.inclusiveNamespaces.indexOf(l.localName)&&c.push({prefix:l.localName,namespaceURI:l.nodeValue})}for(c.sort(a),p=0;p<c.length;++p)i+=" xmlns:"+c[p].prefix+'="'+r.attributeEntities(c[p].namespaceURI)+'"';return{rendered:i,newDefaultNamespace:o,newPrefixesInScope:s}},o.prototype._renderComment=function(e){var t=null,n=null;if(e.ownerDocument===e.parentNode){for(var i=e,o=e;null!==i;){if(i===e.ownerDocument.documentElement){t=!0;break}i=i.nextSibling}for(;null!==o;){if(o===e.ownerDocument.documentElement){n=!0;break}o=o.previousSibling}}return(n?"\n":"")+"\x3c!--"+r.textEntities(e.data)+"--\x3e"+(t?"\n":"")},o.prototype._renderProcessingInstruction=function(e){if("xml"===e.tagName)return"";var t=null,n=null;if(e.ownerDocument===e.parentNode){for(var i=e,o=e;null!==i;){if(i===e.ownerDocument.documentElement){t=!0;break}i=i.nextSibling}for(;null!==o;){if(o===e.ownerDocument.documentElement){n=!0;break}o=o.previousSibling}}return(n?"\n":"")+"<?"+e.tagName+(e.data?" "+r.textEntities(e.data):"")+"?>"+(t?"\n":"")},o.prototype._processInner=function(e,t,n){if(n=n||"",t=t||[],3===e.nodeType)return e.ownerDocument===e.parentNode?r.textEntities(e.data.trim()):r.textEntities(e.data);if(7===e.nodeType)return this._renderProcessingInstruction(e);if(8===e.nodeType)return this.includeComments?this._renderComment(e):"";if(10===e.nodeType)return"";var i=this._renderNamespace(e,t,n),o=this;return[e.tagName?"<"+e.tagName+i.rendered+this._renderAttributes(e)+">":"",[].slice.call(e.childNodes).map((function(e){return o._processInner(e,i.newPrefixesInScope,i.newDefaultNamespace)})).join(""),e.tagName?"</"+e.tagName+">":""].join("")}},418:(e,t)=>{var n=t.entities={"&":"&amp;",'"':"&quot;","<":"&lt;",">":"&gt;","\t":"&#x9;","\n":"&#xA;","\r":"&#xD;"};t.attributeEntities=function(e){return e.replace(/([\&<"\t\n\r])/g,(function(e){return n[e]}))},t.textEntities=function(e){return e.replace(/([\&<>\r])/g,(function(e){return n[e]}))}}},t={},n=function n(r){var i=t[r];if(void 0!==i)return i.exports;var o=t[r]={exports:{}};return e[r](o,o.exports,n),o.exports}(237);window["xml-c14n-sync.js"]=n})();
\ No newline at end of file
diff --git a/src/canonical-xhtml.xsl b/src/canonical-xhtml.xsl
index a815c53..50cb113 100644
--- a/src/canonical-xhtml.xsl
+++ b/src/canonical-xhtml.xsl
@@ -29,8 +29,9 @@ version="3.0">
     RDFa attributes and pre whitespace are never touched; text is never reflowed.
 -->
 
-    <!-- serialization is the caller's job (view-source serialize(), test -o output);
-         no xsl:output here - it would conflict with the including stylesheet's -->
+    <!-- serialization is the caller's job (view-source runs exclusive XML c14n via
+         local:canonicalize-xml in edit.xsl, tests use -o output); no xsl:output
+         here - it would conflict with the including stylesheet's -->
     <xsl:mode name="canonical" on-no-match="shallow-copy"/>
     <xsl:mode name="cm-normalize" on-no-match="shallow-copy"/>
 
diff --git a/src/edit.xsl b/src/edit.xsl
index 883c937..7cc1cbc 100644
--- a/src/edit.xsl
+++ b/src/edit.xsl
@@ -2465,6 +2465,16 @@ version="3.0">
 
     <!-- ................................ view source ................................ -->
 
+    <!-- W3C Exclusive XML Canonicalization (the rdf:XMLLiteral value space) via the
+         xml-c14n lib on the host page - LinkedDataHub's ldh:canonicalize-xml ported.
+         parse-xml() is the XDM->DOM bridge: the lib walks browser DOM nodes, not
+         Saxon's temporary trees -->
+    <xsl:function name="local:canonicalize-xml" as="xs:string">
+        <xsl:param name="doc" as="document-node()"/>
+        <xsl:variable name="js-function" select="ixsl:eval('(function (doc) { return window[''xml-c14n-sync.js'']().createCanonicaliser(''http://www.w3.org/2001/10/xml-exc-c14n#WithComments'').canonicaliseSync(doc.documentElement); })')"/>
+        <xsl:sequence select="ixsl:call($js-function, 'call', [ (), $doc ])"/>
+    </xsl:function>
+
     <xsl:template match="button[@id = 'view-source']" mode="ixsl:onclick">
         <xsl:variable name="canonical" as="element()?">
             <xsl:call-template name="canonical-xhtml">
@@ -2473,7 +2483,7 @@ version="3.0">
         </xsl:variable>
         <xsl:call-template name="local:show-output">
             <xsl:with-param name="title" select="'Canonical XHTML+RDFa'"/>
-            <xsl:with-param name="text" select="serialize($canonical, map{ 'method': 'xml', 'indent': true() })"/>
+            <xsl:with-param name="text" select="local:canonicalize-xml(parse-xml(serialize($canonical, map{ 'method': 'xml' })))"/>
         </xsl:call-template>
     </xsl:template>
 
diff --git a/tests/fixture-dragnest.html b/tests/fixture-dragnest.html
index d235aa7..54bc0fe 100644
--- a/tests/fixture-dragnest.html
+++ b/tests/fixture-dragnest.html
@@ -5,6 +5,7 @@
         <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
         <title>RDFa Editor - nested drag-and-drop fixture</title>
         <script type="text/javascript" src="../lib/SaxonJS3.js"></script>
+		  <script type="text/javascript" src="../lib/xml-c14n-sync.js"></script>
         <script type="text/javascript">
             window.onload = function() {
                 const vocabs = ["vocabs/foaf.rdf", "vocabs/dcterms.rdf"];
diff --git a/tests/fixture-nesting.html b/tests/fixture-nesting.html
index 140dc67..e7d4984 100644
--- a/tests/fixture-nesting.html
+++ b/tests/fixture-nesting.html
@@ -5,6 +5,7 @@
         <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
         <title>RDFa Editor - nesting fixture</title>
         <script type="text/javascript" src="../lib/SaxonJS3.js"></script>
+		  <script type="text/javascript" src="../lib/xml-c14n-sync.js"></script>
         <script type="text/javascript">
             window.onload = function() {
                 const vocabs = ["vocabs/foaf.rdf", "vocabs/dcterms.rdf"];
diff --git a/tests/fixture.html b/tests/fixture.html
index e61c601..af3bb62 100644
--- a/tests/fixture.html
+++ b/tests/fixture.html
@@ -6,6 +6,7 @@
 		<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,400,500,700" type="text/css">
         <title>RDFa Editor</title>
 		  <script type="text/javascript" src="../lib/SaxonJS3.js"></script>
+		  <script type="text/javascript" src="../lib/xml-c14n-sync.js"></script>
 		  <script type="text/javascript">
 				window.onload = function() {
 					// preload the vocabulary documents into the SaxonJS document pool,