diff --git a/src/__celerity_resource_map__.php b/src/__celerity_resource_map__.php
index 83f42b1e8f..ec56888e31 100644
--- a/src/__celerity_resource_map__.php
+++ b/src/__celerity_resource_map__.php
@@ -330,6 +330,17 @@ celerity_register_resource_map(array(
     ),
     'disk' => '/rsrc/js/javelin/lib/behavior.js',
   ),
+  0 =>
+  array(
+    'uri' => '/res/b6096fdd/rsrc/js/javelin/lib/__tests__/URI.js',
+    'type' => 'js',
+    'requires' =>
+    array(
+      0 => 'javelin-uri',
+      1 => 'javelin-php-serializer',
+    ),
+    'disk' => '/rsrc/js/javelin/lib/__tests__/URI.js',
+  ),
   'javelin-behavior-aphront-basic-tokenizer' =>
   array(
     'uri' => '/res/9be30797/rsrc/js/application/core/behavior-tokenizer.js',
@@ -461,7 +472,7 @@ celerity_register_resource_map(array(
   ),
   'javelin-behavior-differential-dropdown-menus' =>
   array(
-    'uri' => '/res/7bfb2fdb/rsrc/js/application/differential/behavior-dropdown-menus.js',
+    'uri' => '/res/4bb3ae9a/rsrc/js/application/differential/behavior-dropdown-menus.js',
     'type' => 'js',
     'requires' =>
     array(
@@ -616,6 +627,19 @@ celerity_register_resource_map(array(
     ),
     'disk' => '/rsrc/js/application/herald/herald-rule-editor.js',
   ),
+  'javelin-behavior-maniphest-description-preview' =>
+  array(
+    'uri' => '/res/8acd6f07/rsrc/js/application/maniphest/behavior-task-preview.js',
+    'type' => 'js',
+    'requires' =>
+    array(
+      0 => 'javelin-behavior',
+      1 => 'javelin-dom',
+      2 => 'javelin-util',
+      3 => 'phabricator-shaped-request',
+    ),
+    'disk' => '/rsrc/js/application/maniphest/behavior-task-preview.js',
+  ),
   'javelin-behavior-maniphest-project-create' =>
   array(
     'uri' => '/res/85a0eaf9/rsrc/js/application/maniphest/behavior-project-create.js',
@@ -1228,6 +1252,15 @@ celerity_register_resource_map(array(
     ),
     'disk' => '/rsrc/css/application/maniphest/task-detail.css',
   ),
+  'maniphest-task-edit-css' =>
+  array(
+    'uri' => '/res/68c7863e/rsrc/css/application/maniphest/task-edit.css',
+    'type' => 'css',
+    'requires' =>
+    array(
+    ),
+    'disk' => '/rsrc/css/application/maniphest/task-edit.css',
+  ),
   'maniphest-task-summary-css' =>
   array(
     'uri' => '/res/14cb4b5d/rsrc/css/application/maniphest/task-summary.css',
@@ -1427,6 +1460,18 @@ celerity_register_resource_map(array(
     ),
     'disk' => '/rsrc/css/application/objectselector/object-selector.css',
   ),
+  'phabricator-prefab' =>
+  array(
+    'uri' => '/res/5784a112/rsrc/js/application/core/Prefab.js',
+    'type' => 'js',
+    'requires' =>
+    array(
+      0 => 'javelin-install',
+      1 => 'javelin-util',
+      2 => 'javelin-dom',
+    ),
+    'disk' => '/rsrc/js/application/core/Prefab.js',
+  ),
   'phabricator-profile-css' =>
   array(
     'uri' => '/res/9869d10b/rsrc/css/application/profile/profile-view.css',
@@ -1445,29 +1490,6 @@ celerity_register_resource_map(array(
     ),
     'disk' => '/rsrc/css/application/profile/profile-header-view.css',
   ),
-  0 =>
-  array(
-    'uri' => '/res/b6096fdd/rsrc/js/javelin/lib/__tests__/URI.js',
-    'type' => 'js',
-    'requires' =>
-    array(
-      0 => 'javelin-uri',
-      1 => 'javelin-php-serializer',
-    ),
-    'disk' => '/rsrc/js/javelin/lib/__tests__/URI.js',
-  ),
-  'phabricator-prefab' =>
-  array(
-    'uri' => '/res/5784a112/rsrc/js/application/core/Prefab.js',
-    'type' => 'js',
-    'requires' =>
-    array(
-      0 => 'javelin-install',
-      1 => 'javelin-util',
-      2 => 'javelin-dom',
-    ),
-    'disk' => '/rsrc/js/application/core/Prefab.js',
-  ),
   'phabricator-remarkup-css' =>
   array(
     'uri' => '/res/39f358b8/rsrc/css/core/remarkup.css',
diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
index 548dbfc977..9f68af8a2c 100644
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -387,6 +387,7 @@ phutil_register_library_map(array(
     'ManiphestTask' => 'applications/maniphest/storage/task',
     'ManiphestTaskAuxiliaryStorage' => 'applications/maniphest/storage/auxiliary',
     'ManiphestTaskDescriptionChangeController' => 'applications/maniphest/controller/descriptionchange',
+    'ManiphestTaskDescriptionPreviewController' => 'applications/maniphest/controller/descriptionpreview',
     'ManiphestTaskDetailController' => 'applications/maniphest/controller/taskdetail',
     'ManiphestTaskEditController' => 'applications/maniphest/controller/taskedit',
     'ManiphestTaskExtensions' => 'applications/maniphest/extensions/base',
@@ -1113,6 +1114,7 @@ phutil_register_library_map(array(
     'ManiphestTask' => 'ManiphestDAO',
     'ManiphestTaskAuxiliaryStorage' => 'ManiphestDAO',
     'ManiphestTaskDescriptionChangeController' => 'ManiphestController',
+    'ManiphestTaskDescriptionPreviewController' => 'ManiphestController',
     'ManiphestTaskDetailController' => 'ManiphestController',
     'ManiphestTaskEditController' => 'ManiphestController',
     'ManiphestTaskListController' => 'ManiphestController',
diff --git a/src/aphront/default/configuration/AphrontDefaultApplicationConfiguration.php b/src/aphront/default/configuration/AphrontDefaultApplicationConfiguration.php
index 6636fc274d..79f3a88461 100644
--- a/src/aphront/default/configuration/AphrontDefaultApplicationConfiguration.php
+++ b/src/aphront/default/configuration/AphrontDefaultApplicationConfiguration.php
@@ -167,6 +167,8 @@ class AphrontDefaultApplicationConfiguration
           'edit/(?P<id>\d+)/$' => 'ManiphestTaskEditController',
           'descriptionchange/(?P<id>\d+)/$' =>
             'ManiphestTaskDescriptionChangeController',
+          'descriptionpreview/$' =>
+            'ManiphestTaskDescriptionPreviewController',
         ),
         'transaction/' => array(
           'save/' => 'ManiphestTransactionSaveController',
diff --git a/src/applications/maniphest/controller/descriptionpreview/ManiphestTaskDescriptionPreviewController.php b/src/applications/maniphest/controller/descriptionpreview/ManiphestTaskDescriptionPreviewController.php
new file mode 100644
index 0000000000..5d1f2b8ad3
--- /dev/null
+++ b/src/applications/maniphest/controller/descriptionpreview/ManiphestTaskDescriptionPreviewController.php
@@ -0,0 +1,41 @@
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * 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.
+ */
+
+/**
+ * @group maniphest
+ */
+class ManiphestTaskDescriptionPreviewController extends ManiphestController {
+
+  public function processRequest() {
+
+    $request = $this->getRequest();
+    $description = $request->getStr('description');
+
+    $engine = PhabricatorMarkupEngine::newManiphestMarkupEngine();
+
+    $content =
+      '<div class="maniphest-task-description">'.
+        '<div class="phabricator-remarkup">'.
+          $engine->markupText($description).
+        '</div>'.
+      '</div>';
+
+    return id(new AphrontAjaxResponse())
+      ->setContent($content);
+  }
+}
diff --git a/src/applications/maniphest/controller/descriptionpreview/__init__.php b/src/applications/maniphest/controller/descriptionpreview/__init__.php
new file mode 100644
index 0000000000..b8c055d996
--- /dev/null
+++ b/src/applications/maniphest/controller/descriptionpreview/__init__.php
@@ -0,0 +1,16 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'aphront/response/ajax');
+phutil_require_module('phabricator', 'applications/maniphest/controller/base');
+phutil_require_module('phabricator', 'applications/markup/engine');
+
+phutil_require_module('phutil', 'utils');
+
+
+phutil_require_source('ManiphestTaskDescriptionPreviewController.php');
diff --git a/src/applications/maniphest/controller/taskedit/ManiphestTaskEditController.php b/src/applications/maniphest/controller/taskedit/ManiphestTaskEditController.php
index 044cc733b9..a0cb108668 100644
--- a/src/applications/maniphest/controller/taskedit/ManiphestTaskEditController.php
+++ b/src/applications/maniphest/controller/taskedit/ManiphestTaskEditController.php
@@ -1,7 +1,7 @@
 <?php
 
 /*
- * Copyright 2011 Facebook, Inc.
+ * Copyright 2012 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -341,6 +341,8 @@ class ManiphestTaskEditController extends ManiphestController {
       $header_name = 'Create New Task';
     }
 
+    require_celerity_resource('maniphest-task-edit-css');
+
     $project_tokenizer_id = celerity_generate_unique_node_id();
 
     $form = new AphrontFormView();
@@ -478,6 +480,7 @@ class ManiphestTaskEditController extends ManiphestController {
         id(new AphrontFormTextAreaControl())
           ->setLabel('Description')
           ->setName('description')
+          ->setID('description-textarea')
           ->setCaption($email_hint)
           ->setValue($task->getDescription()));
 
@@ -503,13 +506,34 @@ class ManiphestTaskEditController extends ManiphestController {
     $panel->setID($panel_id);
     $panel->appendChild($form);
 
+    $description_preview_panel =
+      '<div class="aphront-panel-preview aphront-panel-preview-full">
+        <div class="maniphest-description-preview-header">
+          Description Preview
+        </div>
+        <div id="description-preview">
+          <div class="aphront-panel-preview-loading-text">
+            Loading preview...
+          </div>
+        </div>
+      </div>';
+
+    Javelin::initBehavior(
+      'maniphest-description-preview',
+      array(
+        'preview'   => 'description-preview',
+        'textarea'  => 'description-textarea',
+        'uri'       => '/maniphest/task/descriptionpreview/',
+      ));
+
     return $this->buildStandardPageResponse(
       array(
         $error_view,
         $panel,
+        $description_preview_panel
       ),
       array(
-        'title' => 'Create Task',
+        'title' => $header_name,
       ));
   }
 }
diff --git a/webroot/rsrc/css/application/maniphest/task-edit.css b/webroot/rsrc/css/application/maniphest/task-edit.css
new file mode 100644
index 0000000000..7e25c1698e
--- /dev/null
+++ b/webroot/rsrc/css/application/maniphest/task-edit.css
@@ -0,0 +1,9 @@
+/**
+ * @provides maniphest-task-edit-css
+ */
+
+.maniphest-description-preview-header {
+  color: #666;
+  margin-bottom: 1em;
+  font-size: 11px;
+}
diff --git a/webroot/rsrc/js/application/maniphest/behavior-task-preview.js b/webroot/rsrc/js/application/maniphest/behavior-task-preview.js
new file mode 100644
index 0000000000..c9293f1235
--- /dev/null
+++ b/webroot/rsrc/js/application/maniphest/behavior-task-preview.js
@@ -0,0 +1,29 @@
+/**
+ * @provides javelin-behavior-maniphest-description-preview
+ * @requires javelin-behavior
+ *           javelin-dom
+ *           javelin-util
+ *           phabricator-shaped-request
+ */
+
+JX.behavior('maniphest-description-preview', function(config) {
+
+  var preview = JX.$(config.preview);
+  var textarea = JX.$(config.textarea);
+
+  var callback = function(r) {
+    JX.DOM.setContent(JX.$(config.preview), JX.$H(r));
+  };
+
+  var getdata = function() {
+    return {
+      description : textarea.value
+    };
+  }
+
+  var request = new JX.PhabricatorShapedRequest(config.uri, callback, getdata);
+  var trigger = JX.bind(request, request.trigger);
+
+  JX.DOM.listen(textarea, 'keydown', null, trigger);
+  request.start();
+});