diff --git a/cms/envs/common.py b/cms/envs/common.py
index 3e57f1b064fa..f9bc75a82cf3 100644
--- a/cms/envs/common.py
+++ b/cms/envs/common.py
@@ -1000,6 +1000,11 @@
 ##### EMBARGO #####
 EMBARGO_SITE_REDIRECT_URL = None
 
+##### custom vendor plugin variables #####
+# JavaScript code can access this data using `process.env.JS_ENV_EXTRA_CONFIG`
+# One of the current use cases for this is enabling custom TinyMCE plugins
+JS_ENV_EXTRA_CONFIG = {}
+
 ############################### PIPELINE #######################################
 
 PIPELINE = {
diff --git a/common/lib/xmodule/xmodule/js/src/html/edit.js b/common/lib/xmodule/xmodule/js/src/html/edit.js
index a86cf21cf811..33accebc07c3 100644
--- a/common/lib/xmodule/xmodule/js/src/html/edit.js
+++ b/common/lib/xmodule/xmodule/js/src/html/edit.js
@@ -95,7 +95,8 @@
         tinyMCE incorrectly decides that the suffix should be "", which means it fails to load files.
          */
         tinyMCE.suffix = ".min";
-        this.tiny_mce_textarea = $(".tiny-mce", this.element).tinymce({
+
+        var tinyMceConfig = {
           script_url: baseUrl + "js/vendor/tinymce/js/tinymce/tinymce.full.min.js",
           font_formats: _getFonts(),
           theme: "modern",
@@ -171,7 +172,41 @@
            */
           init_instance_callback: this.initInstanceCallback,
           browser_spellcheck: true
-        });
+        };
+
+        if (typeof process != "undefined" && process.env.JS_ENV_EXTRA_CONFIG) {
+          var tinyMceAdditionalPlugins = process.env.JS_ENV_EXTRA_CONFIG.TINYMCE_ADDITIONAL_PLUGINS;
+          // check if we have any additional plugins passed
+          if (tinyMceAdditionalPlugins) {
+            // go over each plugin
+            tinyMceAdditionalPlugins.forEach(function (tinyMcePlugin) {
+              // check if plugins is not empty (ie there are existing plugins)
+              if (tinyMceConfig.plugins.trim()) {
+                tinyMceConfig.plugins += ', ';
+              }
+
+              // add the plugin to the list of plugins
+              tinyMceConfig.plugins += tinyMcePlugin.name;
+
+              // check if the plugin should be included in the toolbar
+              if (tinyMcePlugin.toolbar) {
+                // check if toolbar is not empty (ie there are already items in the toolbar)
+                if (tinyMceConfig.toolbar.trim()) {
+                  tinyMceConfig.toolbar += ' | ';
+                }
+
+                tinyMceConfig.toolbar += tinyMcePlugin.name;
+              }
+
+              // add the additional settings for each plugin (if there is any)
+              if (tinyMcePlugin.extra_settings) {
+                tinyMceConfig[tinyMcePlugin.name] = tinyMcePlugin.extra_settings;
+              }
+            });
+          }
+        }
+
+        this.tiny_mce_textarea = $(".tiny-mce", this.element).tinymce(tinyMceConfig);
         tinymce.addI18n('en', {
 
           /*
diff --git a/pavelib/assets.py b/pavelib/assets.py
index 1fe27b3a10ef..cdde0d7e3a96 100644
--- a/pavelib/assets.py
+++ b/pavelib/assets.py
@@ -5,7 +5,9 @@
 
 import argparse
 import glob
+import json
 import os
+import re
 import traceback
 from datetime import datetime
 from functools import wraps
@@ -763,14 +765,35 @@ def webpack(options):
     """
     Run a Webpack build.
     """
+    def json_format_setting(setting_value):
+        """
+        Replaces capitalized booleans with booleans that
+        are compatible with parsed JSON in javascript.
+        """
+        if isinstance(setting_value, str):
+            # replace python bools with json valid bools
+            setting_value = re.sub(r'(\:\s?)True', r'\1true', setting_value)
+            setting_value = re.sub(r'(\:\s?)False', r'\1false', setting_value)
+
+            setting_value = setting_value.replace("'", '"')
+
+        return setting_value
+
     settings = getattr(options, 'settings', Env.DEVSTACK_SETTINGS)
     static_root_lms = Env.get_django_setting("STATIC_ROOT", "lms", settings=settings)
     static_root_cms = Env.get_django_setting("STATIC_ROOT", "cms", settings=settings)
     config_path = Env.get_django_setting("WEBPACK_CONFIG_PATH", "lms", settings=settings)
-    environment = u'NODE_ENV={node_env} STATIC_ROOT_LMS={static_root_lms} STATIC_ROOT_CMS={static_root_cms}'.format(
+    js_env_extra_config_setting = Env.get_django_setting("JS_ENV_EXTRA_CONFIG", "cms", settings=settings)
+    js_env_extra_config_json_setting = json.loads(json_format_setting(js_env_extra_config_setting) or '{}')
+    js_env_extra_config = json.dumps(json.dumps(js_env_extra_config_json_setting, sort_keys=True))
+    environment = (
+        u'NODE_ENV={node_env} STATIC_ROOT_LMS={static_root_lms} STATIC_ROOT_CMS={static_root_cms} '
+        u'JS_ENV_EXTRA_CONFIG={js_env_extra_config}'
+    ).format(
         node_env="development" if config_path == 'webpack.dev.config.js' else "production",
         static_root_lms=static_root_lms,
-        static_root_cms=static_root_cms
+        static_root_cms=static_root_cms,
+        js_env_extra_config=js_env_extra_config,
     )
     sh(
         cmd(
diff --git a/pavelib/paver_tests/test_servers.py b/pavelib/paver_tests/test_servers.py
index be69d8d5f319..fa90849fdc66 100644
--- a/pavelib/paver_tests/test_servers.py
+++ b/pavelib/paver_tests/test_servers.py
@@ -1,6 +1,8 @@
 """Unit tests for the Paver server tasks."""
 
 
+import json
+
 import ddt
 from paver.easy import call_task
 
@@ -46,10 +48,12 @@
 EXPECTED_PRINT_SETTINGS_COMMAND = [
     u"python manage.py lms --settings={settings} print_setting STATIC_ROOT 2>{log_file}",
     u"python manage.py cms --settings={settings} print_setting STATIC_ROOT 2>{log_file}",
-    u"python manage.py lms --settings={settings} print_setting WEBPACK_CONFIG_PATH 2>{log_file}"
+    u"python manage.py lms --settings={settings} print_setting WEBPACK_CONFIG_PATH 2>{log_file}",
+    u"python manage.py cms --settings={settings} print_setting JS_ENV_EXTRA_CONFIG 2>{log_file}",
 ]
 EXPECTED_WEBPACK_COMMAND = (
     u"NODE_ENV={node_env} STATIC_ROOT_LMS={static_root_lms} STATIC_ROOT_CMS={static_root_cms} "
+    u"JS_ENV_EXTRA_CONFIG={js_env_extra_config} "
     u"$(npm bin)/webpack --config={webpack_config_path}"
 )
 
@@ -252,6 +256,7 @@ def verify_server_task(self, task_name, options, contracts_default=False):
                 node_env="production",
                 static_root_lms=None,
                 static_root_cms=None,
+                js_env_extra_config=json.dumps({}),
                 webpack_config_path=None
             ))
             expected_messages.extend(self.expected_sass_commands(system=system, asset_settings=expected_asset_settings))
@@ -298,6 +303,7 @@ def verify_run_all_servers_task(self, options):
                 node_env="production",
                 static_root_lms=None,
                 static_root_cms=None,
+                js_env_extra_config=json.dumps({}),
                 webpack_config_path=None
             ))
             expected_messages.extend(self.expected_sass_commands(asset_settings=expected_asset_settings))
diff --git a/webpack.dev.config.js b/webpack.dev.config.js
index 913d773caca3..05f75385c8ca 100644
--- a/webpack.dev.config.js
+++ b/webpack.dev.config.js
@@ -20,7 +20,8 @@ module.exports = _.values(Merge.smart(commonConfig, {
                 debug: true
             }),
             new webpack.DefinePlugin({
-                'process.env.NODE_ENV': JSON.stringify('development')
+                'process.env.NODE_ENV': JSON.stringify('development'),
+                'process.env.JS_ENV_EXTRA_CONFIG': process.env.JS_ENV_EXTRA_CONFIG
             })
         ],
         module: {
diff --git a/webpack.prod.config.js b/webpack.prod.config.js
index 360ab56d4d01..dc85e4efae3b 100644
--- a/webpack.prod.config.js
+++ b/webpack.prod.config.js
@@ -17,7 +17,8 @@ var optimizedConfig = Merge.smart(commonConfig, {
     devtool: false,
     plugins: [
         new webpack.DefinePlugin({
-            'process.env.NODE_ENV': JSON.stringify('production')
+            'process.env.NODE_ENV': JSON.stringify('production'),
+            'process.env.JS_ENV_EXTRA_CONFIG': process.env.JS_ENV_EXTRA_CONFIG
         }),
         new webpack.LoaderOptionsPlugin({  // This may not be needed; legacy option for loaders written for webpack 1
             minimize: true