diff --git a/resources/celerity/map.php b/resources/celerity/map.php
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -8,10 +8,10 @@
 return array(
   'names' => array(
     'core.pkg.css' => '8abb1666',
-    'core.pkg.js' => '573e6664',
+    'core.pkg.js' => 'a79eed25',
     'darkconsole.pkg.js' => 'e7393ebb',
     'differential.pkg.css' => '2de124c9',
-    'differential.pkg.js' => 'f83532f8',
+    'differential.pkg.js' => '5c2ba922',
     'diffusion.pkg.css' => 'f45955ed',
     'diffusion.pkg.js' => '3a9a8bfa',
     'maniphest.pkg.css' => '4845691a',
@@ -192,8 +192,8 @@
     'rsrc/externals/font/lato/lato-regular.ttf' => 'e270165b',
     'rsrc/externals/font/lato/lato-regular.woff' => '13d39fe2',
     'rsrc/externals/font/lato/lato-regular.woff2' => '57a9f742',
-    'rsrc/externals/javelin/core/Event.js' => '85ea0626',
-    'rsrc/externals/javelin/core/Stratcom.js' => '6c53634d',
+    'rsrc/externals/javelin/core/Event.js' => '2ee659ce',
+    'rsrc/externals/javelin/core/Stratcom.js' => '6ad39b6f',
     'rsrc/externals/javelin/core/__tests__/event-stop-and-kill.js' => '717554e4',
     'rsrc/externals/javelin/core/__tests__/install.js' => 'c432ee85',
     'rsrc/externals/javelin/core/__tests__/stratcom.js' => '88bf7313',
@@ -379,7 +379,7 @@
     'rsrc/js/application/differential/behavior-comment-preview.js' => 'b064af76',
     'rsrc/js/application/differential/behavior-diff-radios.js' => 'e1ff79b1',
     'rsrc/js/application/differential/behavior-dropdown-menus.js' => '9a6b9324',
-    'rsrc/js/application/differential/behavior-edit-inline-comments.js' => '65ef6074',
+    'rsrc/js/application/differential/behavior-edit-inline-comments.js' => '4fbbc3e9',
     'rsrc/js/application/differential/behavior-keyboard-nav.js' => '2c426492',
     'rsrc/js/application/differential/behavior-populate.js' => '8694b1df',
     'rsrc/js/application/differential/behavior-toggle-files.js' => 'ca3f91eb',
@@ -465,7 +465,7 @@
     'rsrc/js/core/behavior-choose-control.js' => '327a00d1',
     'rsrc/js/core/behavior-crop.js' => 'fa0f4fc2',
     'rsrc/js/core/behavior-dark-console.js' => 'f411b6ae',
-    'rsrc/js/core/behavior-device.js' => 'a205cf28',
+    'rsrc/js/core/behavior-device.js' => 'b5b36110',
     'rsrc/js/core/behavior-drag-and-drop-textarea.js' => '4f6a4b4e',
     'rsrc/js/core/behavior-error-log.js' => '6882e80a',
     'rsrc/js/core/behavior-fancy-datepicker.js' => '8ae55229',
@@ -584,12 +584,12 @@
     'javelin-behavior-dashboard-tab-panel' => 'd4eecc63',
     'javelin-behavior-day-view' => '5c46cff2',
     'javelin-behavior-desktop-notifications-control' => 'edd1ba66',
-    'javelin-behavior-device' => 'a205cf28',
+    'javelin-behavior-device' => 'b5b36110',
     'javelin-behavior-differential-add-reviewers-and-ccs' => 'e10f8e18',
     'javelin-behavior-differential-comment-jump' => '4fdb476d',
     'javelin-behavior-differential-diff-radios' => 'e1ff79b1',
     'javelin-behavior-differential-dropdown-menus' => '9a6b9324',
-    'javelin-behavior-differential-edit-inline-comments' => '65ef6074',
+    'javelin-behavior-differential-edit-inline-comments' => '4fbbc3e9',
     'javelin-behavior-differential-feedback-preview' => 'b064af76',
     'javelin-behavior-differential-keyboard-navigation' => '2c426492',
     'javelin-behavior-differential-populate' => '8694b1df',
@@ -683,7 +683,7 @@
     'javelin-diffusion-locate-file-source' => 'b42eddc7',
     'javelin-dom' => '805b806a',
     'javelin-dynval' => 'f6555212',
-    'javelin-event' => '85ea0626',
+    'javelin-event' => '2ee659ce',
     'javelin-fx' => '54b612ba',
     'javelin-history' => 'd4505101',
     'javelin-install' => '05270951',
@@ -702,7 +702,7 @@
     'javelin-router' => '29274e2b',
     'javelin-scrollbar' => '087e919c',
     'javelin-sound' => '949c0fe5',
-    'javelin-stratcom' => '6c53634d',
+    'javelin-stratcom' => '6ad39b6f',
     'javelin-tokenizer' => '8d3bc1b2',
     'javelin-typeahead' => '70baed2f',
     'javelin-typeahead-composite-source' => '503e17fd',
@@ -1050,6 +1050,9 @@
       'javelin-install',
       'javelin-event',
     ),
+    '2ee659ce' => array(
+      'javelin-install',
+    ),
     '327a00d1' => array(
       'javelin-behavior',
       'javelin-stratcom',
@@ -1164,6 +1167,14 @@
       'phabricator-drag-and-drop-file-upload',
       'phabricator-textareautils',
     ),
+    '4fbbc3e9' => array(
+      'javelin-behavior',
+      'javelin-stratcom',
+      'javelin-dom',
+      'javelin-util',
+      'javelin-vector',
+      'differential-inline-comment-editor',
+    ),
     '4fdb476d' => array(
       'javelin-behavior',
       'javelin-stratcom',
@@ -1295,14 +1306,6 @@
       'javelin-request',
       'javelin-workflow',
     ),
-    '65ef6074' => array(
-      'javelin-behavior',
-      'javelin-stratcom',
-      'javelin-dom',
-      'javelin-util',
-      'javelin-vector',
-      'differential-inline-comment-editor',
-    ),
     '66dd6e9e' => array(
       'javelin-behavior',
       'javelin-behavior-device',
@@ -1316,6 +1319,12 @@
     '69adf288' => array(
       'javelin-install',
     ),
+    '6ad39b6f' => array(
+      'javelin-install',
+      'javelin-event',
+      'javelin-util',
+      'javelin-magical-init',
+    ),
     '6b8ef10b' => array(
       'javelin-install',
     ),
@@ -1327,12 +1336,6 @@
       'javelin-install',
       'javelin-util',
     ),
-    '6c53634d' => array(
-      'javelin-install',
-      'javelin-event',
-      'javelin-util',
-      'javelin-magical-init',
-    ),
     '6d3e1947' => array(
       'javelin-behavior',
       'javelin-diffusion-locate-file-source',
@@ -1446,9 +1449,6 @@
       'javelin-dom',
       'javelin-stratcom',
     ),
-    '85ea0626' => array(
-      'javelin-install',
-    ),
     '85ee8ce6' => array(
       'aphront-dialog-view-css',
     ),
@@ -1602,13 +1602,6 @@
       'javelin-vector',
       'javelin-magical-init',
     ),
-    'a205cf28' => array(
-      'javelin-behavior',
-      'javelin-stratcom',
-      'javelin-dom',
-      'javelin-vector',
-      'javelin-install',
-    ),
     'a2828756' => array(
       'javelin-dom',
       'javelin-util',
@@ -1739,6 +1732,13 @@
       'javelin-dom',
       'phabricator-draggable-list',
     ),
+    'b5b36110' => array(
+      'javelin-behavior',
+      'javelin-stratcom',
+      'javelin-dom',
+      'javelin-vector',
+      'javelin-install',
+    ),
     'b5c256b8' => array(
       'javelin-install',
       'javelin-dom',
diff --git a/webroot/rsrc/externals/javelin/core/Event.js b/webroot/rsrc/externals/javelin/core/Event.js
--- a/webroot/rsrc/externals/javelin/core/Event.js
+++ b/webroot/rsrc/externals/javelin/core/Event.js
@@ -326,7 +326,16 @@
     /**
      * @task info
      */
-    nodeDistances : {}
+    nodeDistances : {},
+
+    /**
+     * True if this is a cursor event that was caused by a touch interaction
+     * rather than a mouse device interaction.
+     *
+     * @type bool
+     * @taks info
+     */
+    isTouchEvent: false
   },
 
   /**
@@ -339,7 +348,13 @@
     if (__DEV__) {
       JX.Event.prototype.toString = function() {
         var path = '['+this.getPath().join(', ')+']';
-        return 'Event<'+this.getType()+', '+path+', '+this.getTarget()+'>';
+
+        var type = this.getType();
+        if (this.getIsTouchEvent()) {
+          type = type + '/touch';
+        }
+
+        return 'Event<'+type+', '+path+', '+this.getTarget()+'>';
       };
     }
   }
diff --git a/webroot/rsrc/externals/javelin/core/Stratcom.js b/webroot/rsrc/externals/javelin/core/Stratcom.js
--- a/webroot/rsrc/externals/javelin/core/Stratcom.js
+++ b/webroot/rsrc/externals/javelin/core/Stratcom.js
@@ -41,6 +41,7 @@
     _auto : '*',
     _data : {},
     _execContext : [],
+    _touchState: null,
 
     /**
      * Node metadata is stored in a series of blocks to prevent collisions
@@ -330,6 +331,45 @@
         etype = 'blur';
       }
 
+      // Map of touch events and whether they are unique per touch.
+      var touch_map = {
+        touchstart: true,
+        touchend: true,
+        mousedown: true,
+        mouseup: true,
+        click: true,
+
+        // These can conceivably fire multiple times per touch, so if we see
+        // them more than once that doesn't tell us that we're handling a new
+        // event.
+        mouseover: false,
+        mouseout: false,
+        mousemove: false,
+        touchmove: false
+      };
+
+      // If this is a 'touchstart', we're handling touch events.
+      if (etype == 'touchstart') {
+        this._touchState = {};
+      }
+
+      // If this is a unique touch event that we haven't seen before, remember
+      // it as part of the current touch state. On the other hand, if we've
+      // already seen it, we can deduce that we must be handling a new cursor
+      // event that is unrelated to the last touch we saw, and conclude that
+      // we are no longer processing a touch event.
+      if (touch_map[etype] && this._touchState) {
+        if (!this._touchState[etype]) {
+          this._touchState[etype] = true;
+        } else {
+          this._touchState = null;
+        }
+      }
+
+      // This event is a touch event if we're carrying some touch state.
+      var is_touch = (etype in touch_map) &&
+                     (this._touchState !== null);
+
       var proxy = new JX.Event()
         .setRawEvent(event)
         .setData(event.customData)
@@ -337,9 +377,11 @@
         .setTarget(target)
         .setNodes(nodes)
         .setNodeDistances(distances)
+        .setIsTouchEvent(is_touch)
         .setPath(path.reverse());
 
-      // Don't touch this for debugging purposes
+      // You can uncomment this to print out all events flowing through
+      // Stratcom, which tends to make debugging easier.
       //JX.log('~> '+proxy.toString());
 
       return this._dispatchProxy(proxy);
diff --git a/webroot/rsrc/js/application/differential/behavior-edit-inline-comments.js b/webroot/rsrc/js/application/differential/behavior-edit-inline-comments.js
--- a/webroot/rsrc/js/application/differential/behavior-edit-inline-comments.js
+++ b/webroot/rsrc/js/application/differential/behavior-edit-inline-comments.js
@@ -22,6 +22,26 @@
 
   var editor = null;
 
+  function updateReticleForComment(e) {
+    root = e.getNode('differential-changeset');
+    if (!root) {
+      return;
+    }
+
+    var data = e.getNodeData('differential-inline-comment');
+    var change = e.getNodeData('differential-changeset');
+
+    var id_part = data.on_right ? change.right : change.left;
+    var new_part = data.isNewFile ? 'N' : 'O';
+    var prefix = 'C' + id_part + new_part + 'L';
+
+    origin = JX.$(prefix + data.number);
+    target = JX.$(prefix + (parseInt(data.number, 10) +
+                            parseInt(data.length, 10)));
+
+    updateReticle();
+  }
+
   function updateReticle() {
     JX.DOM.getContentFrame().appendChild(reticle);
 
@@ -176,6 +196,10 @@
     ['mouseover', 'mouseout'],
     ['differential-changeset', 'tag:th'],
     function(e) {
+      if (e.getIsTouchEvent()) {
+        return;
+      }
+
       if (editor) {
         // Don't update the reticle if we're editing a comment, since this
         // would be distracting and we want to keep the lines corresponding
@@ -274,24 +298,14 @@
     ['mouseover', 'mouseout'],
     'differential-inline-comment',
     function(e) {
+      if (e.getIsTouchEvent()) {
+        return;
+      }
+
       if (e.getType() == 'mouseout') {
         hideReticle();
       } else {
-        root = e.getNode('differential-changeset');
-        if (root) {
-          var data = e.getNodeData('differential-inline-comment');
-          var change = e.getNodeData('differential-changeset');
-
-          var id_part = data.on_right ? change.right : change.left;
-          var new_part = data.isNewFile ? 'N' : 'O';
-          var prefix = 'C' + id_part + new_part + 'L';
-
-          origin = JX.$(prefix + data.number);
-          target = JX.$(prefix + (parseInt(data.number, 10) +
-                                  parseInt(data.length, 10)));
-
-          updateReticle();
-        }
+        updateReticleForComment(e);
       }
     });
 
@@ -303,6 +317,12 @@
     }
 
     var node = e.getNode('differential-inline-comment');
+
+    // If we're on a touch device, we didn't highlight the affected lines
+    // earlier because we can't use hover events to mutate the document.
+    // Highlight them now.
+    updateReticleForComment(e);
+
     handle_inline_action(node, op);
   };
 
diff --git a/webroot/rsrc/js/core/behavior-device.js b/webroot/rsrc/js/core/behavior-device.js
--- a/webroot/rsrc/js/core/behavior-device.js
+++ b/webroot/rsrc/js/core/behavior-device.js
@@ -62,6 +62,11 @@
       JX.Stratcom.invoke('phabricator-device-change', null, device);
     },
 
+    isDesktop: function() {
+      var self = JX.Device;
+      return (self.getDevice() == 'desktop');
+    },
+
     getDevice : function() {
       var self = JX.Device;
       if (self._device === null) {