diff --git a/unpacked/config/default.js b/unpacked/config/default.js
index 030ddecd0..878efdd38 100644
--- a/unpacked/config/default.js
+++ b/unpacked/config/default.js
@@ -961,6 +961,20 @@ MathJax.Hub.Config({
     showFontMenu: false,
     showContext:  false,
     showDiscoverable: false,
+    
+    //
+    // These are the settings for the Annotation menu. If the <math> root has
+    // a <semantics> child that contains one of the following annotation
+    // formats, the source will be available via the "Show Math As" menu.
+    // Each format has a list of possible encodings.
+    //
+    semanticsAnnotations: {
+      "TeX": ["TeX", "LaTeX", "application/x-tex"],
+      "StarMath": ["StarMath 5.0"],
+      "Maple": ["Maple"],
+      "ContentMathML": ["MathML-Content", "application/mathml-content+xml"],
+      "OpenMath": ["OpenMath"]
+    },
 
     //
     //  These are the settings for the Show Source window.  The initial
diff --git a/unpacked/extensions/MathEvents.js b/unpacked/extensions/MathEvents.js
index 552a079d2..0b16a229a 100644
--- a/unpacked/extensions/MathEvents.js
+++ b/unpacked/extensions/MathEvents.js
@@ -161,6 +161,24 @@
 	  source.items[0].name = jax.sourceMenuTitle;
 	  source.items[0].format = (jax.sourceMenuFormat||"MathML");
           source.items[1].name = INPUT[jax.inputJax].sourceMenuTitle;
+
+          // 
+          // Try and find each known annotation format and enable the menu
+          // items accordingly.
+          //
+          var annotations = source.items[2]; annotations.disabled = true;
+          var annotationItems = annotations.menu.items;
+          annotationList = MathJax.Hub.Config.semanticsAnnotations;
+          for (var i = 0, m = annotationItems.length; i < m; i++) {
+            var name = annotationItems[i].name[1]
+            if (jax.root.getAnnotation(name) !== null) {
+              annotations.disabled = false;
+              annotationItems[i].hidden = false;
+            } else {
+              annotationItems[i].hidden = true;
+            }
+          }
+
           var MathPlayer = MENU.menu.Find("Math Settings","MathPlayer");
           MathPlayer.hidden = !(jax.outputJax === "NativeMML" && HUB.Browser.hasMathPlayer);
           return MENU.menu.Post(event);
diff --git a/unpacked/extensions/MathMenu.js b/unpacked/extensions/MathMenu.js
index 1e2aa945e..78fa39161 100644
--- a/unpacked/extensions/MathMenu.js
+++ b/unpacked/extensions/MathMenu.js
@@ -58,6 +58,14 @@
     showLocale: true,                              //  show the "Locale" menu?
     showLocaleURL: false,                          //  show the "Load from URL" menu?
 
+    semanticsAnnotations: {
+      "TeX": ["TeX", "LaTeX", "application/x-tex"],
+      "StarMath": ["StarMath 5.0"],
+      "Maple": ["Maple"],
+      "ContentMathML": ["MathML-Content", "application/mathml-content+xml"],
+      "OpenMath": ["OpenMath"]
+    },
+
     windowSettings: {                              // for source window
       status: "no", toolbar: "no", locationbar: "no", menubar: "no",
       directories: "no", personalbar: "no", resizable: "yes", scrollbars: "yes",
@@ -711,6 +719,9 @@
       }
     } else if (this.format === "Error") {
       MENU.ShowSource.Text(MENU.jax.errorText,event);
+    } else if (CONFIG.semanticsAnnotations[this.format]) {
+      var annotation = MENU.jax.root.getAnnotation(this.format);
+      if (annotation.data[0]) MENU.ShowSource.Text(annotation.data[0].toString());
     } else {
       if (MENU.jax.originalText == null) {
         alert(_("NoOriginalForm","No original form available"));
@@ -989,6 +1000,20 @@
     menu.items.push(items[items.length-2],items[items.length-1]);
   };
 
+  //
+  // Create the annotation menu from MathJax.Hub.config.semanticsAnnotations
+  //
+  MENU.CreateAnnotationMenu = function () {
+    if (!MENU.menu) return;
+    var menu = MENU.menu.Find("Show Math As","Annotation").menu;
+    var annotations = CONFIG.semanticsAnnotations;
+    for (var a in annotations) {
+      if (annotations.hasOwnProperty(a)) {
+        menu.items.push(ITEM.COMMAND([a,a], MENU.ShowSource, {hidden: true, nativeTouch: true, format: a}));
+      }
+    }
+  };
+
   /*************************************************************/
 
   HUB.Register.StartupHook("End Config",function () {
@@ -1012,6 +1037,7 @@
       ITEM.SUBMENU(["Show","Show Math As"],
         ITEM.COMMAND(["MathMLcode","MathML Code"],  MENU.ShowSource, {nativeTouch: true, format: "MathML"}),
         ITEM.COMMAND(["Original","Original Form"],  MENU.ShowSource, {nativeTouch: true}),
+        ITEM.SUBMENU(["Annotation","Annotation"], {disabled:true}),
         ITEM.RULE(),
         ITEM.CHECKBOX(["texHints","Show TeX hints in MathML"], "texHints")
       ),
@@ -1095,6 +1121,7 @@
     }
 
     MENU.CreateLocaleMenu();
+    MENU.CreateAnnotationMenu();
   });
   
   MENU.showRenderer = function (show) {
diff --git a/unpacked/jax/element/mml/jax.js b/unpacked/jax/element/mml/jax.js
index ecc457a48..64fc492f2 100644
--- a/unpacked/jax/element/mml/jax.js
+++ b/unpacked/jax/element/mml/jax.js
@@ -380,7 +380,8 @@ MathJax.ElementJax.mml.Augment({
       return false;
     },
     array: function () {if (this.inferred) {return this.data} else {return [this]}},
-    toString: function () {return this.type+"("+this.data.join(",")+")"}
+    toString: function () {return this.type+"("+this.data.join(",")+")"},
+    getAnnotation: function () { return null; }
   },{
     childrenSpacelike: function () {
       for (var i = 0, m = this.data.length; i < m; i++)
@@ -731,6 +732,10 @@ MathJax.ElementJax.mml.Augment({
         {if (this.data[i]) {prev = this.data[i].setTeXclass(prev)}}
       if (this.data[0]) {this.updateTeXclass(this.data[0])}
       return prev;
+    },
+    getAnnotation: function (name) {
+      if (this.data.length != 1) return null;
+      return this.data[0].getAnnotation(name);
     }
   });
 
@@ -1175,7 +1180,21 @@ MathJax.ElementJax.mml.Augment({
       definitionURL: null,
       encoding: null
     },
-    setTeXclass: MML.mbase.setChildTeXclass
+    setTeXclass: MML.mbase.setChildTeXclass,
+    getAnnotation: function (name) {
+      var encodingList = MathJax.Hub.config.MathMenu.semanticsAnnotations[name];
+      if (encodingList) {
+        for (var i = 0, m = this.data.length; i < m; i++) {
+          var encoding = this.data[i].Get("encoding");
+          if (encoding) {
+            for (var j = 0, n = encodingList.length; j < n; j++) {
+              if (encodingList[j] === encoding) return this.data[i];
+            }
+          }
+        }
+      }
+      return null;
+    }
   });
   MML.annotation = MML.mbase.Subclass({
     type: "annotation", isToken: true,
@@ -1236,7 +1255,11 @@ MathJax.ElementJax.mml.Augment({
       return "";
     },
     linebreakContainer: true,
-    setTeXclass: MML.mbase.setChildTeXclass
+    setTeXclass: MML.mbase.setChildTeXclass,
+    getAnnotation: function (name) {
+      if (this.data.length != 1) return null;
+      return this.data[0].getAnnotation(name);
+    }
   });
   
   MML.chars = MML.mbase.Subclass({