diff --git a/components/bin/build b/components/bin/build
index e045ddd0a..d9a9d5836 100755
--- a/components/bin/build
+++ b/components/bin/build
@@ -30,7 +30,7 @@ const path = require('path');
 /**
  * The amount of space for each level of indentation
  */
-const INDENT = '    ';
+const INDENT = '  ';
 
 /**
  * The pattern to use when looking for explort commands to process
@@ -51,17 +51,28 @@ const mjGlobal = path.join('..', mjPath, 'components', 'global.js');
  */
 const config = JSON.parse(fs.readFileSync(process.argv[2] || 'build.json'));
 
+function getType() {
+  const component = config.component || 'part';
+  if (component.match(/\/(svg|chtml|common)\/fonts\//)) return RegExp.$1 + '-font';
+  if (component.match(/\/(mathml|tex)\/.+\//)) return RegExp.$1 + '-extension';
+  if (component.match(/^(.+)\//)) return RegExp.$1;
+  return component;
+}
+
 /**
  * Extract the configuration values
  */
 const COMPONENT = path.basename(config.component || 'part');                // name of the component
+const ID = config.id || config.component || 'part';                         // the ID of the component
 const TARGETS = config.targets || [];                                       // the files to include in the component
 const EXCLUDE = new Map((config.exclude || []).map(name => [name, true]));  // files to exclude from the component
 const EXCLUDESUBDIRS = config.excludeSubdirs === 'true';                    // exclude subdirectories or not
 const JS = config.js || config.mathjax || mjPath;                           // path to the compiled .js files
 const LIB = config.lib || './lib';                                          // path to the lib directory to create
-const GLOBAL = config.global || mjGlobal;                                   // path to the global.js file
 const TS = config.ts || JS.replace(/js$/, 'ts');                            // path to the .ts files
+const GLOBAL = config.global || mjGlobal;                                   // path to the global.js file
+const VERSION = config.version || mjGlobal.replace(/global/, 'version');    // path to the version.js file
+const TYPE = config.type || getType();                                      // the module type
 
 /**
  * The list of files that need to be added to the lib directory
@@ -222,6 +233,7 @@ function processGlobal() {
   console.info('  ' + COMPONENT + '.ts');
   const lines = [
     `import {combineWithMathJax} from '${GLOBAL}';`,
+    `import {VERSION} from '${VERSION}';`,
     '',
   ];
   const packages = [];
@@ -230,9 +242,17 @@ function processGlobal() {
     const dir = path.dirname(PACKAGE[0]).split(path.sep)[0];
     packages.push(processPackage(lines, INDENT, dir));
   }
-  lines.push('', `combineWithMathJax({_: {`);
-  lines.push(INDENT + packages.join(',\n' + INDENT));
-  lines.push('}});');
+  const name = (ID.match(/[^a-zA-Z0-9_]/) ? `"${ID}"` : ID);
+  lines.push(
+    '',
+    'if (MathJax.loader) {',
+      INDENT + `MathJax.loader.checkVersion('${ID}', VERSION, '${TYPE}');`,
+    '}',
+    '',
+    `combineWithMathJax({_: {`,
+      INDENT + packages.join(',\n' + INDENT),
+    '}});'
+  );
   fs.writeFileSync(path.join(LIB, COMPONENT + '.js'), lines.join('\n') + '\n');
 }
 
diff --git a/components/src/input/mml/build.json b/components/src/input/mml/build.json
index a41d8dfdd..d4864a0f5 100644
--- a/components/src/input/mml/build.json
+++ b/components/src/input/mml/build.json
@@ -1,5 +1,5 @@
 {
-  "component": "inpu/mml",
+  "component": "input/mml",
   "targets": [
     "input/mathml.ts",
     "input/mathml"
diff --git a/components/src/input/mml/extensions/mml3/build.json b/components/src/input/mml/extensions/mml3/build.json
index 1de76ca6f..6ae79ed71 100644
--- a/components/src/input/mml/extensions/mml3/build.json
+++ b/components/src/input/mml/extensions/mml3/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[mml]/mml3",
   "component": "input/mml/extensions/mml3",
   "targets": ["input/mathml/mml3"]
 }
diff --git a/components/src/input/tex/extensions/action/build.json b/components/src/input/tex/extensions/action/build.json
index 5c2aa0f8d..a0b6af601 100644
--- a/components/src/input/tex/extensions/action/build.json
+++ b/components/src/input/tex/extensions/action/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/action",
   "component": "input/tex/extensions/action",
   "targets": ["input/tex/action"]
 }
diff --git a/components/src/input/tex/extensions/all-packages/build.json b/components/src/input/tex/extensions/all-packages/build.json
index 098cf185e..216671f99 100644
--- a/components/src/input/tex/extensions/all-packages/build.json
+++ b/components/src/input/tex/extensions/all-packages/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/all-packages",
   "component": "input/tex/extensions/all-packages",
   "targets": [
     "input/tex/AllPackages.ts",
diff --git a/components/src/input/tex/extensions/ams/build.json b/components/src/input/tex/extensions/ams/build.json
index a2a1d4002..865acc303 100644
--- a/components/src/input/tex/extensions/ams/build.json
+++ b/components/src/input/tex/extensions/ams/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/ams",
   "component": "input/tex/extensions/ams",
   "targets": ["input/tex/ams"]
 }
diff --git a/components/src/input/tex/extensions/amscd/build.json b/components/src/input/tex/extensions/amscd/build.json
index 477406992..6c3fc87ea 100644
--- a/components/src/input/tex/extensions/amscd/build.json
+++ b/components/src/input/tex/extensions/amscd/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/amscd",
   "component": "input/tex/extensions/amscd",
   "targets": ["input/tex/amscd"]
 }
diff --git a/components/src/input/tex/extensions/autoload/build.json b/components/src/input/tex/extensions/autoload/build.json
index e19f7f6d5..d4f9b89e0 100644
--- a/components/src/input/tex/extensions/autoload/build.json
+++ b/components/src/input/tex/extensions/autoload/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/autoload",
   "component": "input/tex/extensions/autoload",
   "targets": ["input/tex/autoload"]
 }
diff --git a/components/src/input/tex/extensions/bbox/build.json b/components/src/input/tex/extensions/bbox/build.json
index 3741b8738..c50918558 100644
--- a/components/src/input/tex/extensions/bbox/build.json
+++ b/components/src/input/tex/extensions/bbox/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/bbox",
   "component": "input/tex/extensions/bbox",
   "targets": ["input/tex/bbox"]
 }
diff --git a/components/src/input/tex/extensions/boldsymbol/build.json b/components/src/input/tex/extensions/boldsymbol/build.json
index 7e5deedbd..3d59f0cb2 100644
--- a/components/src/input/tex/extensions/boldsymbol/build.json
+++ b/components/src/input/tex/extensions/boldsymbol/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/boldsymbol",
   "component": "input/tex/extensions/boldsymbol",
   "targets": ["input/tex/boldsymbol"]
 }
diff --git a/components/src/input/tex/extensions/braket/build.json b/components/src/input/tex/extensions/braket/build.json
index 5e2924725..c0631d751 100644
--- a/components/src/input/tex/extensions/braket/build.json
+++ b/components/src/input/tex/extensions/braket/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/braket",
   "component": "input/tex/extensions/braket",
   "targets": ["input/tex/braket"]
 }
diff --git a/components/src/input/tex/extensions/bussproofs/build.json b/components/src/input/tex/extensions/bussproofs/build.json
index 8cf99265b..242e91f16 100644
--- a/components/src/input/tex/extensions/bussproofs/build.json
+++ b/components/src/input/tex/extensions/bussproofs/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/bussproofs",
   "component": "input/tex/extensions/bussproofs",
   "targets": ["input/tex/bussproofs"]
 }
diff --git a/components/src/input/tex/extensions/cancel/build.json b/components/src/input/tex/extensions/cancel/build.json
index f06e1e858..9577e4e95 100644
--- a/components/src/input/tex/extensions/cancel/build.json
+++ b/components/src/input/tex/extensions/cancel/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/cancel",
   "component": "input/tex/extensions/cancel",
   "targets": ["input/tex/cancel"]
 }
diff --git a/components/src/input/tex/extensions/cases/build.json b/components/src/input/tex/extensions/cases/build.json
index b7549fde4..b4be43cbc 100644
--- a/components/src/input/tex/extensions/cases/build.json
+++ b/components/src/input/tex/extensions/cases/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/cases",
   "component": "input/tex/extensions/cases",
   "targets": ["input/tex/cases"]
 }
diff --git a/components/src/input/tex/extensions/centernot/build.json b/components/src/input/tex/extensions/centernot/build.json
index e754ff18a..1ebcd76b6 100644
--- a/components/src/input/tex/extensions/centernot/build.json
+++ b/components/src/input/tex/extensions/centernot/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/centernot",
   "component": "input/tex/extensions/centernot",
   "targets": ["input/tex/centernot"]
 }
diff --git a/components/src/input/tex/extensions/color/build.json b/components/src/input/tex/extensions/color/build.json
index 98e4923e3..3e8614c11 100644
--- a/components/src/input/tex/extensions/color/build.json
+++ b/components/src/input/tex/extensions/color/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/color",
   "component": "input/tex/extensions/color",
   "targets": ["input/tex/color"]
 }
diff --git a/components/src/input/tex/extensions/colortbl/build.json b/components/src/input/tex/extensions/colortbl/build.json
index 5b2e25c68..cf70b9a7d 100644
--- a/components/src/input/tex/extensions/colortbl/build.json
+++ b/components/src/input/tex/extensions/colortbl/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/colortbl",
   "component": "input/tex/extensions/colortbl",
   "targets": ["input/tex/colortbl"]
 }
diff --git a/components/src/input/tex/extensions/colorv2/build.json b/components/src/input/tex/extensions/colorv2/build.json
index 3923daa18..0710e56e4 100644
--- a/components/src/input/tex/extensions/colorv2/build.json
+++ b/components/src/input/tex/extensions/colorv2/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/colorv2",
   "component": "input/tex/extensions/colorv2",
   "targets": ["input/tex/colorv2"]
 }
diff --git a/components/src/input/tex/extensions/configmacros/build.json b/components/src/input/tex/extensions/configmacros/build.json
index 0496ad45a..809b5d94c 100644
--- a/components/src/input/tex/extensions/configmacros/build.json
+++ b/components/src/input/tex/extensions/configmacros/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/configmacros",
   "component": "input/tex/extensions/configmacros",
   "targets": ["input/tex/configmacros"]
 }
diff --git a/components/src/input/tex/extensions/empheq/build.json b/components/src/input/tex/extensions/empheq/build.json
index 681da096b..f0563a9b2 100644
--- a/components/src/input/tex/extensions/empheq/build.json
+++ b/components/src/input/tex/extensions/empheq/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/empheq",
   "component": "input/tex/extensions/empheq",
   "targets": ["input/tex/empheq"]
 }
diff --git a/components/src/input/tex/extensions/enclose/build.json b/components/src/input/tex/extensions/enclose/build.json
index 07e3978e7..ebf489c82 100644
--- a/components/src/input/tex/extensions/enclose/build.json
+++ b/components/src/input/tex/extensions/enclose/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/enclose",
   "component": "input/tex/extensions/enclose",
   "targets": ["input/tex/enclose"]
 }
diff --git a/components/src/input/tex/extensions/extpfeil/build.json b/components/src/input/tex/extensions/extpfeil/build.json
index 7f5fa8bd5..37378a525 100644
--- a/components/src/input/tex/extensions/extpfeil/build.json
+++ b/components/src/input/tex/extensions/extpfeil/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/extpfeil",
   "component": "input/tex/extensions/extpfeil",
   "targets": ["input/tex/extpfeil"]
 }
diff --git a/components/src/input/tex/extensions/gensymb/build.json b/components/src/input/tex/extensions/gensymb/build.json
index 0d976916e..220fe879d 100644
--- a/components/src/input/tex/extensions/gensymb/build.json
+++ b/components/src/input/tex/extensions/gensymb/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/gensymb",
   "component": "input/tex/extensions/gensymb",
   "targets": ["input/tex/gensymb"]
 }
diff --git a/components/src/input/tex/extensions/html/build.json b/components/src/input/tex/extensions/html/build.json
index 886436843..7ee5d20ac 100644
--- a/components/src/input/tex/extensions/html/build.json
+++ b/components/src/input/tex/extensions/html/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/html",
   "component": "input/tex/extensions/html",
   "targets": ["input/tex/html"]
 }
diff --git a/components/src/input/tex/extensions/mathtools/build.json b/components/src/input/tex/extensions/mathtools/build.json
index 22021cfd5..b00ef3147 100644
--- a/components/src/input/tex/extensions/mathtools/build.json
+++ b/components/src/input/tex/extensions/mathtools/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/mathtools",
   "component": "input/tex/extensions/mathtools",
   "targets": ["input/tex/mathtools"]
 }
diff --git a/components/src/input/tex/extensions/mhchem/build.json b/components/src/input/tex/extensions/mhchem/build.json
index e79f6127f..e7728bdad 100644
--- a/components/src/input/tex/extensions/mhchem/build.json
+++ b/components/src/input/tex/extensions/mhchem/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/mhchem",
   "component": "input/tex/extensions/mhchem",
   "targets": ["input/tex/mhchem"],
   "exclude": ["input/tex/mhchem/mhchem_parser.d.ts"]
diff --git a/components/src/input/tex/extensions/newcommand/build.json b/components/src/input/tex/extensions/newcommand/build.json
index 9a3eb23a3..119063b2f 100644
--- a/components/src/input/tex/extensions/newcommand/build.json
+++ b/components/src/input/tex/extensions/newcommand/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/newcommand",
   "component": "input/tex/extensions/newcommand",
   "targets": ["input/tex/newcommand"]
 }
diff --git a/components/src/input/tex/extensions/noerrors/build.json b/components/src/input/tex/extensions/noerrors/build.json
index c35696db6..dae2b51e0 100644
--- a/components/src/input/tex/extensions/noerrors/build.json
+++ b/components/src/input/tex/extensions/noerrors/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/noerrors",
   "component": "input/tex/extensions/noerrors",
   "targets": ["input/tex/noerrors"]
 }
diff --git a/components/src/input/tex/extensions/noundefined/build.json b/components/src/input/tex/extensions/noundefined/build.json
index 177e0e78a..3ea2d344c 100644
--- a/components/src/input/tex/extensions/noundefined/build.json
+++ b/components/src/input/tex/extensions/noundefined/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/noundefined",
   "component": "input/tex/extensions/noundefined",
   "targets": ["input/tex/noundefined"]
 }
diff --git a/components/src/input/tex/extensions/physics/build.json b/components/src/input/tex/extensions/physics/build.json
index 962363e25..b0ba5aaec 100644
--- a/components/src/input/tex/extensions/physics/build.json
+++ b/components/src/input/tex/extensions/physics/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/physics",
   "component": "input/tex/extensions/physics",
   "targets": ["input/tex/physics"]
 }
diff --git a/components/src/input/tex/extensions/require/build.json b/components/src/input/tex/extensions/require/build.json
index a39792c56..594088cfc 100644
--- a/components/src/input/tex/extensions/require/build.json
+++ b/components/src/input/tex/extensions/require/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/require",
   "component": "input/tex/extensions/require",
   "targets": ["input/tex/require"]
 }
diff --git a/components/src/input/tex/extensions/setoptions/build.json b/components/src/input/tex/extensions/setoptions/build.json
index d703672ac..f7171fd64 100644
--- a/components/src/input/tex/extensions/setoptions/build.json
+++ b/components/src/input/tex/extensions/setoptions/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/setoptions",
   "component": "input/tex/extensions/setoptions",
   "targets": ["input/tex/setoptions"]
 }
diff --git a/components/src/input/tex/extensions/tagformat/build.json b/components/src/input/tex/extensions/tagformat/build.json
index 9562f5403..e56479448 100644
--- a/components/src/input/tex/extensions/tagformat/build.json
+++ b/components/src/input/tex/extensions/tagformat/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/tagformat",
   "component": "input/tex/extensions/tagformat",
   "targets": ["input/tex/tagformat"]
 }
diff --git a/components/src/input/tex/extensions/textcomp/build.json b/components/src/input/tex/extensions/textcomp/build.json
index fe61189ae..dc88ae71c 100644
--- a/components/src/input/tex/extensions/textcomp/build.json
+++ b/components/src/input/tex/extensions/textcomp/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/textcomp",
   "component": "input/tex/extensions/textcomp",
   "targets": ["input/tex/textcomp"]
 }
diff --git a/components/src/input/tex/extensions/textmacros/build.json b/components/src/input/tex/extensions/textmacros/build.json
index ecd01e28b..80b0e02d9 100644
--- a/components/src/input/tex/extensions/textmacros/build.json
+++ b/components/src/input/tex/extensions/textmacros/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/textmacros",
   "component": "input/tex/extensions/textmacros",
   "targets": ["input/tex/textmacros"]
 }
diff --git a/components/src/input/tex/extensions/unicode/build.json b/components/src/input/tex/extensions/unicode/build.json
index 9340bb190..2e7604802 100644
--- a/components/src/input/tex/extensions/unicode/build.json
+++ b/components/src/input/tex/extensions/unicode/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/unicode",
   "component": "input/tex/extensions/unicode",
   "targets": ["input/tex/unicode"]
 }
diff --git a/components/src/input/tex/extensions/upgreek/build.json b/components/src/input/tex/extensions/upgreek/build.json
index 2bda780bf..70c9812ea 100644
--- a/components/src/input/tex/extensions/upgreek/build.json
+++ b/components/src/input/tex/extensions/upgreek/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/upgreek",
   "component": "input/tex/extensions/upgreek",
   "targets": ["input/tex/upgreek"]
 }
diff --git a/components/src/input/tex/extensions/verb/build.json b/components/src/input/tex/extensions/verb/build.json
index ad4d0e183..53f726931 100644
--- a/components/src/input/tex/extensions/verb/build.json
+++ b/components/src/input/tex/extensions/verb/build.json
@@ -1,4 +1,5 @@
 {
+  "id": "[tex]/verb",
   "component": "input/tex/extensions/verb",
   "targets": ["input/tex/verb"]
 }
diff --git a/components/webpack.common.js b/components/webpack.common.js
index 8edfdd893..034b98810 100644
--- a/components/webpack.common.js
+++ b/components/webpack.common.js
@@ -46,11 +46,15 @@ function quoteRE(string) {
 const PLUGINS = function (js, dir) {
   const mjdir = path.resolve(__dirname, '..', 'js');
   const jsdir = path.resolve(dir, js);
+  const package = path.resolve(__dirname, '..', 'package.json');
 
   //
   //  Record the js directory for the pack command
   //
-  return [new webpack.DefinePlugin({__JSDIR__: jsdir})];
+  return [new webpack.DefinePlugin({
+    __JSDIR__: jsdir,
+    PACKAGE_VERSION: `'${require(package).version}'`
+  })];
 };
 
 /**
diff --git a/ts/components/global.ts b/ts/components/global.ts
index e6fafd8ce..d0fee7690 100644
--- a/ts/components/global.ts
+++ b/ts/components/global.ts
@@ -22,6 +22,8 @@
  * @author dpvc@mathjax.org (Davide Cervone)
  */
 
+import {VERSION} from './version.js';
+
 /**
  * The MathJax variable as a configuration object
  */
@@ -127,7 +129,7 @@ if (typeof global.MathJax === 'undefined') {
  */
 if (!(global.MathJax as MathJaxObject).version) {
   global.MathJax = {
-    version: '3.2.0',
+    version: VERSION,
     _: {},
     config: global.MathJax
   };
diff --git a/ts/components/loader.ts b/ts/components/loader.ts
index fa5b2501e..bf4d1f19c 100644
--- a/ts/components/loader.ts
+++ b/ts/components/loader.ts
@@ -58,6 +58,7 @@ export interface MathJaxConfig extends MJConfig {
     failed?: PackageFailed;                    // A function to call when MathJax fails to load
     require?: (url: string) => any;            // A function for loading URLs
     pathFilters?: PathFilterList;              // List of path filters (and optional priorities) to add
+    versionWarnings?: boolean;                 // True means warn when extension version doesn't match MJ version
     [name: string]: any;                       // Other configuration blocks
   };
 }
@@ -74,6 +75,7 @@ export interface MathJaxObject extends MJObject {
     preLoad: (...names: string[]) => void;            // Indicate that packages are already loaded by hand
     defaultReady: () => void;                         // The function performed when all packages are loaded
     getRoot: () => string;                            // Find the root URL for the MathJax files
+    checkVersion: (name: string, version: string) => boolean;   // Check the version of an extension
     pathFilters: FunctionList;                        // the filters to use for looking for package paths
   };
   startup?: any;
@@ -127,6 +129,16 @@ export const PathFilters: {[name: string]: PathFilterFunction} = {
  */
 export namespace Loader {
 
+  /**
+   * The version of MathJax that is running.
+   */
+  const VERSION = MJGlobal.version;
+
+  /**
+   * The versions of all the loaded extensions.
+   */
+  export const versions: Map<string, string> = new Map();
+
   /**
    * Get a promise that is resolved when all the named packages have been loaded.
    *
@@ -163,7 +175,12 @@ export namespace Loader {
         extension.provides(CONFIG.provides[name]);
       }
       extension.checkNoLoad();
-      promises.push(extension.promise);
+      promises.push(extension.promise.then(() => {
+        if (!CONFIG.versionWarnings) return;
+        if (extension.isLoaded && !versions.has(Package.resolvePath(name))) {
+          console.warn(`No version information available for component ${name}`);
+        }
+      }) as Promise<null>);
     }
     Package.loadAll();
     return Promise.all(promises);
@@ -210,6 +227,23 @@ export namespace Loader {
     return root;
   }
 
+  /**
+   * Check the version of an extension and report an error if not correct
+   *
+   * @param {string} name       The name of the extension being checked
+   * @param {string} version    The version of the extension to check
+   * @param {string} type       The type of extension (future code may use this to check ranges of versions)
+   * @return {boolean}          True if there was a mismatch, false otherwise
+   */
+  export function checkVersion(name: string, version: string, _type?: string): boolean {
+    versions.set(Package.resolvePath(name), VERSION);
+    if (CONFIG.versionWarnings && version !== VERSION) {
+      console.warn(`Component ${name} uses ${version} of MathJax; version in use is ${VERSION}`);
+      return true;
+    }
+    return false;
+  }
+
   /**
    * The filters to use to modify the paths used to obtain the packages
    */
@@ -247,6 +281,7 @@ if (typeof MathJax.loader === 'undefined') {
     failed: (error: PackageError) => console.log(`MathJax(${error.package || '?'}): ${error.message}`),
     require: null,
     pathFilters: [],
+    versionWarnings: true
   });
   combineWithMathJax({
     loader: Loader
diff --git a/ts/components/version.ts b/ts/components/version.ts
new file mode 100644
index 000000000..a96fc8277
--- /dev/null
+++ b/ts/components/version.ts
@@ -0,0 +1,44 @@
+/*************************************************************
+ *
+ *  Copyright (c) 2018-2021 The MathJax Consortium
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+/**
+ * @fileoverview  The version of MathJax (used to tell what version a component
+ *                was compiled against).
+ *
+ * @author dpvc@mathjax.org (Davide Cervone)
+ */
+
+declare const PACKAGE_VERSION: string;  // provided by webpack via DefinePlugin
+
+export const VERSION = (
+  typeof PACKAGE_VERSION === 'undefined' ?
+    //
+    //  This will not be included in the webpack version, so only runs in node
+    //
+    (function () {
+      //
+      //  Look up the version from the package.json file
+      //
+      /* tslint:disable-next-line:no-eval */
+      const load = eval('require');
+      /* tslint:disable-next-line:no-eval */
+      const dirname = eval('__dirname');
+      const path = load('path');
+      return load(path.resolve(dirname, '..', '..', 'package.json')).version;
+    })() :
+  PACKAGE_VERSION
+);
diff --git a/ts/mathjax.ts b/ts/mathjax.ts
index 5273bc1b6..41c5b5337 100644
--- a/ts/mathjax.ts
+++ b/ts/mathjax.ts
@@ -21,6 +21,7 @@
  * @author dpvc@mathjax.org (Davide Cervone)
  */
 
+import {VERSION} from './components/version.js';
 import {HandlerList} from './core/HandlerList.js';
 import {handleRetriesFor, retryAfter} from './util/Retries.js';
 import {OptionList} from './util/Options.js';
@@ -34,7 +35,7 @@ export const mathjax = {
   /**
    *  The MathJax version number
    */
-  version: '3.2.0',
+  version: VERSION,
 
   /**
    *  The list of registers document handlers
diff --git a/ts/output/chtml/FontData.ts b/ts/output/chtml/FontData.ts
index 1e45a48ff..23de02dde 100644
--- a/ts/output/chtml/FontData.ts
+++ b/ts/output/chtml/FontData.ts
@@ -73,6 +73,11 @@ export class CHTMLFontData extends FontData<CHTMLCharOptions, CHTMLVariantData,
     fontURL: 'js/output/chtml/fonts/tex-woff-v2'
   };
 
+  /**
+   * @override
+   */
+  public static JAX = 'CHTML';
+
   /**
    * The default class names to use for each variant
    */
diff --git a/ts/output/common/FontData.ts b/ts/output/common/FontData.ts
index d80df6c58..bf745715c 100644
--- a/ts/output/common/FontData.ts
+++ b/ts/output/common/FontData.ts
@@ -243,6 +243,16 @@ export class FontData<C extends CharOptions, V extends VariantData<C>, D extends
     unknownFamily: 'serif'     // Should use 'monospace' with LiteAdaptor
   };
 
+  /**
+   * The name of the output jax this font data is for (used by extensions)
+   */
+  public static JAX: string = 'common';
+
+  /**
+   * The name of the font that is being defined (used by extensions)
+   */
+  public static NAME: string = '';
+
   /**
    *  The standard variants to define
    */
diff --git a/ts/output/common/fonts/tex.ts b/ts/output/common/fonts/tex.ts
index dc1496461..90e239b1e 100644
--- a/ts/output/common/fonts/tex.ts
+++ b/ts/output/common/fonts/tex.ts
@@ -40,6 +40,11 @@ export function CommonTeXFontMixin<
 
   return class extends Base {
 
+    /**
+     * @override
+     */
+    public static NAME = 'TeX';
+
     /**
      *  Add the extra variants for the TeX fonts
      */
diff --git a/ts/output/svg/FontData.ts b/ts/output/svg/FontData.ts
index 9b4d3fcf5..8a67f4b14 100644
--- a/ts/output/svg/FontData.ts
+++ b/ts/output/svg/FontData.ts
@@ -61,6 +61,19 @@ export interface SVGDelimiterData extends DelimiterData {
  */
 export class SVGFontData extends FontData<SVGCharOptions, SVGVariantData, SVGDelimiterData> {
 
+  /**
+   * @override
+   */
+  public static OPTIONS = {
+    ...FontData.OPTIONS,
+    dynamicPrefix: './output/svg/fonts'
+  };
+
+  /**
+   * @override
+   */
+  public static JAX = 'SVG';
+
   /**
    * @override
    */