diff --git a/resources/sql/patches/20121209.pholioxactions.sql b/resources/sql/patches/20121209.pholioxactions.sql
new file mode 100644
index 0000000000..70f2280057
--- /dev/null
+++ b/resources/sql/patches/20121209.pholioxactions.sql
@@ -0,0 +1,51 @@
+DROP TABLE {$NAMESPACE}_pholio.pholio_transaction;
+DROP TABLE {$NAMESPACE}_pholio.pholio_pixelcomment;
+
+CREATE TABLE {$NAMESPACE}_pholio.pholio_transaction (
+  id INT UNSIGNED NOT NULL PRIMARY KEY AUTO_INCREMENT,
+  phid VARCHAR(64) NOT NULL COLLATE utf8_bin,
+  authorPHID VARCHAR(64) NOT NULL COLLATE utf8_bin,
+  objectPHID VARCHAR(64) NOT NULL COLLATE utf8_bin,
+  viewPolicy VARCHAR(64) NOT NULL COLLATE utf8_bin,
+  editPolicy VARCHAR(64) NOT NULL COLLATE utf8_bin,
+  commentPHID VARCHAR(64) COLLATE utf8_bin,
+  commentVersion INT UNSIGNED NOT NULL,
+  transactionType VARCHAR(32) NOT NULL COLLATE utf8_bin,
+  oldValue LONGTEXT NOT NULL COLLATE utf8_bin,
+  newValue LONGTEXT NOT NULL COLLATE utf8_bin,
+  contentSource LONGTEXT NOT NULL COLLATE utf8_bin,
+  dateCreated INT UNSIGNED NOT NULL,
+  dateModified INT UNSIGNED NOT NULL,
+
+  UNIQUE KEY `key_phid` (phid),
+  KEY `key_object` (objectPHID)
+
+) ENGINE=InnoDB, COLLATE utf8_general_ci;
+
+CREATE TABLE {$NAMESPACE}_pholio.pholio_transaction_comment (
+  id INT UNSIGNED NOT NULL PRIMARY KEY AUTO_INCREMENT,
+  phid VARCHAR(64) NOT NULL COLLATE utf8_bin,
+  transactionPHID VARCHAR(64) COLLATE utf8_bin,
+  authorPHID VARCHAR(64) NOT NULL COLLATE utf8_bin,
+  viewPolicy VARCHAR(64) NOT NULL COLLATE utf8_bin,
+  editPolicy VARCHAR(64) NOT NULL COLLATE utf8_bin,
+  commentVersion INT UNSIGNED NOT NULL,
+  content LONGTEXT NOT NULL COLLATE utf8_bin,
+  contentSource LONGTEXT NOT NULL COLLATE utf8_bin,
+  isDeleted BOOL NOT NULL,
+  dateCreated INT UNSIGNED NOT NULL,
+  dateModified INT UNSIGNED NOT NULL,
+
+  mockID INT UNSIGNED,
+  imageID INT UNSIGNED,
+  x INT UNSIGNED,
+  y INT UNSIGNED,
+  width INT UNSIGNED,
+  height INT UNSIGNED,
+
+  UNIQUE KEY `key_phid` (phid),
+  UNIQUE KEY `key_version` (transactionPHID, commentVersion),
+  UNIQUE KEY `key_draft` (authorPHID, mockID, transactionPHID)
+
+) ENGINE=InnoDB, COLLATE utf8_general_ci;
+
diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
index 5a5f8b5854..1580da7510 100644
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -597,6 +597,13 @@ phutil_register_library_map(array(
     'PhabricatorApplicationSlowvote' => 'applications/slowvote/application/PhabricatorApplicationSlowvote.php',
     'PhabricatorApplicationStatusView' => 'applications/meta/view/PhabricatorApplicationStatusView.php',
     'PhabricatorApplicationSubscriptions' => 'applications/subscriptions/application/PhabricatorApplicationSubscriptions.php',
+    'PhabricatorApplicationTransaction' => 'applications/transactions/storage/PhabricatorApplicationTransaction.php',
+    'PhabricatorApplicationTransactionComment' => 'applications/transactions/storage/PhabricatorApplicationTransactionComment.php',
+    'PhabricatorApplicationTransactionCommentEditor' => 'applications/transactions/editor/PhabricatorApplicationTransactionCommentEditor.php',
+    'PhabricatorApplicationTransactionCommentQuery' => 'applications/transactions/query/PhabricatorApplicationTransactionCommentQuery.php',
+    'PhabricatorApplicationTransactionEditor' => 'applications/transactions/editor/PhabricatorApplicationTransactionEditor.php',
+    'PhabricatorApplicationTransactionQuery' => 'applications/transactions/query/PhabricatorApplicationTransactionQuery.php',
+    'PhabricatorApplicationTransactions' => 'applications/transactions/application/PhabricatorApplicationTransactions.php',
     'PhabricatorApplicationUIExamples' => 'applications/uiexample/application/PhabricatorApplicationUIExamples.php',
     'PhabricatorApplicationsListController' => 'applications/meta/controller/PhabricatorApplicationsListController.php',
     'PhabricatorAuditActionConstants' => 'applications/audit/constants/PhabricatorAuditActionConstants.php',
@@ -1129,6 +1136,7 @@ phutil_register_library_map(array(
     'PhabricatorTimelineView' => 'view/layout/PhabricatorTimelineView.php',
     'PhabricatorTimer' => 'applications/countdown/storage/PhabricatorTimer.php',
     'PhabricatorTransactionView' => 'view/layout/PhabricatorTransactionView.php',
+    'PhabricatorTransactions' => 'applications/transactions/constants/PhabricatorTransactions.php',
     'PhabricatorTransformedFile' => 'applications/files/storage/PhabricatorTransformedFile.php',
     'PhabricatorTranslation' => 'infrastructure/internationalization/PhabricatorTranslation.php',
     'PhabricatorTrivialTestCase' => 'infrastructure/testing/__tests__/PhabricatorTrivialTestCase.php',
@@ -1225,9 +1233,9 @@ phutil_register_library_map(array(
     'PholioMockListController' => 'applications/pholio/controller/PholioMockListController.php',
     'PholioMockQuery' => 'applications/pholio/query/PholioMockQuery.php',
     'PholioMockViewController' => 'applications/pholio/controller/PholioMockViewController.php',
-    'PholioPixelComment' => 'applications/pholio/storage/PholioPixelComment.php',
     'PholioReplyHandler' => 'applications/pholio/mail/PholioReplyHandler.php',
     'PholioTransaction' => 'applications/pholio/storage/PholioTransaction.php',
+    'PholioTransactionComment' => 'applications/pholio/storage/PholioTransactionComment.php',
     'PholioTransactionQuery' => 'applications/pholio/query/PholioTransactionQuery.php',
     'PholioTransactionType' => 'applications/pholio/constants/PholioTransactionType.php',
     'PhortuneMonthYearExpiryControl' => 'applications/phortune/control/PhortuneMonthYearExpiryControl.php',
@@ -1843,6 +1851,17 @@ phutil_register_library_map(array(
     'PhabricatorApplicationSlowvote' => 'PhabricatorApplication',
     'PhabricatorApplicationStatusView' => 'AphrontView',
     'PhabricatorApplicationSubscriptions' => 'PhabricatorApplication',
+    'PhabricatorApplicationTransaction' => 'PhabricatorLiskDAO',
+    'PhabricatorApplicationTransactionComment' =>
+    array(
+      0 => 'PhabricatorLiskDAO',
+      1 => 'PhabricatorMarkupInterface',
+    ),
+    'PhabricatorApplicationTransactionCommentEditor' => 'PhabricatorEditor',
+    'PhabricatorApplicationTransactionCommentQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
+    'PhabricatorApplicationTransactionEditor' => 'PhabricatorEditor',
+    'PhabricatorApplicationTransactionQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
+    'PhabricatorApplicationTransactions' => 'PhabricatorApplication',
     'PhabricatorApplicationUIExamples' => 'PhabricatorApplication',
     'PhabricatorApplicationsListController' => 'PhabricatorController',
     'PhabricatorAuditAddCommentController' => 'PhabricatorAuditController',
@@ -2437,21 +2456,13 @@ phutil_register_library_map(array(
     ),
     'PholioMockCommentController' => 'PholioController',
     'PholioMockEditController' => 'PholioController',
-    'PholioMockEditor' => 'PhabricatorEditor',
+    'PholioMockEditor' => 'PhabricatorApplicationTransactionEditor',
     'PholioMockListController' => 'PholioController',
     'PholioMockQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
     'PholioMockViewController' => 'PholioController',
-    'PholioPixelComment' =>
-    array(
-      0 => 'PholioDAO',
-      1 => 'PhabricatorMarkupInterface',
-    ),
     'PholioReplyHandler' => 'PhabricatorMailReplyHandler',
-    'PholioTransaction' =>
-    array(
-      0 => 'PholioDAO',
-      1 => 'PhabricatorMarkupInterface',
-    ),
+    'PholioTransaction' => 'PhabricatorApplicationTransaction',
+    'PholioTransactionComment' => 'PhabricatorApplicationTransactionComment',
     'PholioTransactionQuery' => 'PhabricatorOffsetPagedQuery',
     'PholioTransactionType' => 'PholioConstants',
     'PhortuneMonthYearExpiryControl' => 'AphrontFormControl',
diff --git a/src/applications/phid/PhabricatorPHIDConstants.php b/src/applications/phid/PhabricatorPHIDConstants.php
index c89896381d..fdeb1755c0 100644
--- a/src/applications/phid/PhabricatorPHIDConstants.php
+++ b/src/applications/phid/PhabricatorPHIDConstants.php
@@ -30,4 +30,7 @@ final class PhabricatorPHIDConstants {
   const PHID_TYPE_ANSW    = 'ANSW';
   const PHID_TYPE_MOCK    = 'MOCK';
 
+  const PHID_TYPE_XACT    = 'XACT';
+  const PHID_TYPE_XCMT    = 'XCMT';
+
 }
diff --git a/src/applications/phid/storage/PhabricatorPHID.php b/src/applications/phid/storage/PhabricatorPHID.php
index d73490846d..2e8d114318 100644
--- a/src/applications/phid/storage/PhabricatorPHID.php
+++ b/src/applications/phid/storage/PhabricatorPHID.php
@@ -7,13 +7,21 @@ final class PhabricatorPHID {
   protected $ownerPHID;
   protected $parentPHID;
 
-  public static function generateNewPHID($type) {
+  public static function generateNewPHID($type, $subtype = null) {
     if (!$type) {
       throw new Exception("Can not generate PHID with no type.");
     }
 
-    $uniq = Filesystem::readRandomCharacters(20);
-    return 'PHID-'.$type.'-'.$uniq;
+    if ($subtype === null) {
+      $uniq_len = 20;
+      $type_str = "{$type}";
+    } else {
+      $uniq_len = 15;
+      $type_str = "{$type}-{$subtype}";
+    }
+
+    $uniq = Filesystem::readRandomCharacters($uniq_len);
+    return "PHID-{$type_str}-{$uniq}";
   }
 
   public static function fromObjectName($name) {
diff --git a/src/applications/pholio/constants/PholioTransactionType.php b/src/applications/pholio/constants/PholioTransactionType.php
index 4778370a21..f2227a0401 100644
--- a/src/applications/pholio/constants/PholioTransactionType.php
+++ b/src/applications/pholio/constants/PholioTransactionType.php
@@ -2,10 +2,7 @@
 
 final class PholioTransactionType extends PholioConstants {
 
-  const TYPE_NONE         = 'none';
   const TYPE_NAME         = 'name';
   const TYPE_DESCRIPTION  = 'description';
-  const TYPE_VIEW_POLICY  = 'viewPolicy';
-  const TYPE_SUBSCRIBERS  = 'subscribers';
 
 }
diff --git a/src/applications/pholio/controller/PholioMockCommentController.php b/src/applications/pholio/controller/PholioMockCommentController.php
index b61502a615..62a81906b1 100644
--- a/src/applications/pholio/controller/PholioMockCommentController.php
+++ b/src/applications/pholio/controller/PholioMockCommentController.php
@@ -44,8 +44,10 @@ final class PholioMockCommentController extends PholioController {
       ));
 
     $xaction = id(new PholioTransaction())
-      ->setTransactionType(PholioTransactionType::TYPE_NONE)
-      ->setComment($comment);
+      ->setTransactionType(PhabricatorTransactions::TYPE_COMMENT)
+      ->attachComment(
+        id(new PholioTransactionComment())
+          ->setContent($comment));
 
     id(new PholioMockEditor())
       ->setActor($user)
diff --git a/src/applications/pholio/controller/PholioMockEditController.php b/src/applications/pholio/controller/PholioMockEditController.php
index 1118cba580..5f51366dd4 100644
--- a/src/applications/pholio/controller/PholioMockEditController.php
+++ b/src/applications/pholio/controller/PholioMockEditController.php
@@ -57,7 +57,7 @@ final class PholioMockEditController extends PholioController {
 
       $type_name = PholioTransactionType::TYPE_NAME;
       $type_desc = PholioTransactionType::TYPE_DESCRIPTION;
-      $type_view = PholioTransactionType::TYPE_VIEW_POLICY;
+      $type_view = PhabricatorTransactions::TYPE_VIEW_POLICY;
 
       $v_name = $request->getStr('name');
       $v_desc = $request->getStr('description');
diff --git a/src/applications/pholio/controller/PholioMockViewController.php b/src/applications/pholio/controller/PholioMockViewController.php
index e21c1ac4f2..14867cbf9e 100644
--- a/src/applications/pholio/controller/PholioMockViewController.php
+++ b/src/applications/pholio/controller/PholioMockViewController.php
@@ -25,7 +25,8 @@ final class PholioMockViewController extends PholioController {
     }
 
     $xactions = id(new PholioTransactionQuery())
-      ->withMockIDs(array($mock->getID()))
+      ->setViewer($user)
+      ->withObjectPHIDs(array($mock->getPHID()))
       ->execute();
 
     $subscribers = PhabricatorSubscribersQuery::loadSubscribersForPHID(
@@ -33,12 +34,6 @@ final class PholioMockViewController extends PholioController {
 
     $phids = array();
     $phids[] = $mock->getAuthorPHID();
-    foreach ($xactions as $xaction) {
-      $phids[] = $xaction->getAuthorPHID();
-      foreach ($xaction->getRequiredHandlePHIDs() as $hphid) {
-        $phids[] = $hphid;
-      }
-    }
     foreach ($subscribers as $subscriber) {
       $phids[] = $subscriber;
     }
@@ -49,7 +44,11 @@ final class PholioMockViewController extends PholioController {
       ->setViewer($user);
     $engine->addObject($mock, PholioMock::MARKUP_FIELD_DESCRIPTION);
     foreach ($xactions as $xaction) {
-      $engine->addObject($xaction, PholioTransaction::MARKUP_FIELD_COMMENT);
+      if ($xaction->getComment()) {
+        $engine->addObject(
+          $xaction->getComment(),
+          PholioTransaction::MARKUP_FIELD_COMMENT);
+      }
     }
     $engine->process();
 
@@ -198,113 +197,20 @@ final class PholioMockViewController extends PholioController {
     $view = new PhabricatorTimelineView();
 
     foreach ($xactions as $xaction) {
-      $author = $this->getHandle($xaction->getAuthorPHID());
-
-      $old = $xaction->getOldValue();
-      $new = $xaction->getNewValue();
-
-      $xaction_visible = true;
-      $title = null;
-      $type = $xaction->getTransactionType();
-
-      switch ($type) {
-        case PholioTransactionType::TYPE_NONE:
-          $title = pht(
-            '%s added a comment.',
-            $author->renderLink());
-          break;
-        case PholioTransactionType::TYPE_NAME:
-          if ($old === null) {
-            $xaction_visible = false;
-            break;
-          }
-          $title = pht(
-            '%s renamed this mock from "%s" to "%s".',
-            $author->renderLink(),
-            phutil_escape_html($old),
-            phutil_escape_html($new));
-          break;
-        case PholioTransactionType::TYPE_DESCRIPTION:
-          if ($old === null) {
-            $xaction_visible = false;
-            break;
-          }
-          // TODO: Show diff, like Maniphest.
-          $title = pht(
-            '%s updated the description of this mock. '.
-            'The old description was: %s',
-            $author->renderLink(),
-            phutil_escape_html($old));
-          break;
-        case PholioTransactionType::TYPE_VIEW_POLICY:
-          if ($old === null) {
-            $xaction_visible = false;
-            break;
-          }
-          // TODO: Render human-readable.
-          $title = pht(
-            '%s changed the visibility of this mock from "%s" to "%s".',
-            $author->renderLink(),
-            phutil_escape_html($old),
-            phutil_escape_html($new));
-          break;
-        case PholioTransactionType::TYPE_SUBSCRIBERS:
-          $rem = array_diff($old, $new);
-          $add = array_diff($new, $old);
-
-          $add_l = array();
-          foreach ($add as $phid) {
-            $add_l[] = $this->getHandle($phid)->renderLink();
-          }
-          $add_l = implode(', ', $add_l);
-
-          $rem_l = array();
-          foreach ($rem as $phid) {
-            $rem_l[] = $this->getHandle($phid)->renderLink();
-          }
-          $rem_l = implode(', ', $rem_l);
-
-          if ($add && $rem) {
-            $title = pht(
-              '%s edited subscriber(s), added %d: %s; removed %d: %s.',
-              $author->renderLink(),
-              $add_l,
-              count($add),
-              $rem_l,
-              count($rem));
-          } else if ($add) {
-            $title = pht(
-              '%s added %d subscriber(s): %s.',
-              $author->renderLink(),
-              count($add),
-              $add_l);
-          } else if ($rem) {
-            $title = pht(
-              '%s removed %d subscribers: %s.',
-              $author->renderLink(),
-              count($rem),
-              $rem_l);
-          }
-          break;
-        default:
-          throw new Exception("Unknown transaction type '{$type}'!");
-      }
-
-      if (!$xaction_visible) {
-        // Some transactions aren't useful to human viewers, like
-        // the initial transactions which set the mock's name and description.
+      if ($xaction->shouldHide()) {
         continue;
       }
 
+      $title = $xaction->getTitle();
+
       $event = id(new PhabricatorTimelineEventView())
-        ->setUserHandle($author);
+        ->setUserHandle($xaction->getHandle($xaction->getAuthorPHID()))
+        ->setTitle($title);
 
-      $event->setTitle($title);
-
-      if (strlen($xaction->getComment())) {
+      if ($xaction->getComment()) {
         $event->appendChild(
           $engine->getOutput(
-            $xaction,
+            $xaction->getComment(),
             PholioTransaction::MARKUP_FIELD_COMMENT));
       }
 
diff --git a/src/applications/pholio/editor/PholioMockEditor.php b/src/applications/pholio/editor/PholioMockEditor.php
index 582fb1e61c..d721a60b2a 100644
--- a/src/applications/pholio/editor/PholioMockEditor.php
+++ b/src/applications/pholio/editor/PholioMockEditor.php
@@ -3,111 +3,88 @@
 /**
  * @group pholio
  */
-final class PholioMockEditor extends PhabricatorEditor {
+final class PholioMockEditor extends PhabricatorApplicationTransactionEditor {
 
-  private $contentSource;
+  public function getTransactionTypes() {
+    $types = parent::getTransactionTypes();
 
-  public function setContentSource(PhabricatorContentSource $content_source) {
-    $this->contentSource = $content_source;
-    return $this;
+    $types[] = PhabricatorTransactions::TYPE_VIEW_POLICY;
+    $types[] = PhabricatorTransactions::TYPE_EDIT_POLICY;
+
+    $types[] = PholioTransactionType::TYPE_NAME;
+    $types[] = PholioTransactionType::TYPE_DESCRIPTION;
+    return $types;
   }
 
-  public function getContentSource() {
-    return $this->contentSource;
+  protected function didApplyTransactions(
+    PhabricatorLiskDAO $object,
+    array $xactions) {
+//    $this->sendMail($object, $xactions);
+//    PholioIndexer::indexMock($mock);
+    return;
   }
 
-  public function applyTransactions(PholioMock $mock, array $xactions) {
-    assert_instances_of($xactions, 'PholioTransaction');
+  protected function getCustomTransactionOldValue(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
 
-    $actor = $this->requireActor();
-    if (!$this->contentSource) {
-      throw new Exception(
-        "Call setContentSource() before applyTransactions()!");
+    switch ($xaction->getTransactionType()) {
+      case PholioTransactionType::TYPE_NAME:
+        return $object->getName();
+      case PholioTransactionType::TYPE_DESCRIPTION:
+        return $object->getDescription();
     }
+  }
 
-    $is_new = !$mock->getID();
+  protected function getCustomTransactionNewValue(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
 
-    $comments = array();
-    foreach ($xactions as $xaction) {
-      if (strlen($xaction->getComment())) {
-        $comments[] = $xaction->getComment();
-      }
-      $type = $xaction->getTransactionType();
-      if ($type == PholioTransactionType::TYPE_DESCRIPTION) {
-        $comments[] = $xaction->getNewValue();
-      }
+    switch ($xaction->getTransactionType()) {
+      case PholioTransactionType::TYPE_NAME:
+      case PholioTransactionType::TYPE_DESCRIPTION:
+        return $xaction->getNewValue();
     }
+  }
 
-    $mentioned_phids = PhabricatorMarkupEngine::extractPHIDsFromMentions(
-      $comments);
-    $subscribe_phids = $mentioned_phids;
+  protected function applyCustomInternalTransaction(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
 
-    // Attempt to subscribe the actor.
-    $subscribe_phids[] = $actor->getPHID();
-
-    if ($subscribe_phids) {
-      if ($mock->getID()) {
-        $old_subs = PhabricatorSubscribersQuery::loadSubscribersForPHID(
-          $mock->getPHID());
-      } else {
-        $old_subs = array();
-      }
-
-      $new_subs = array_merge($old_subs, $mentioned_phids);
-      $xaction = id(new PholioTransaction())
-        ->setTransactionType(PholioTransactionType::TYPE_SUBSCRIBERS)
-        ->setOldValue($old_subs)
-        ->setNewValue($new_subs);
-      array_unshift($xactions, $xaction);
-    }
-
-    foreach ($xactions as $xaction) {
-      $xaction->setContentSource($this->contentSource);
-      $xaction->setAuthorPHID($actor->getPHID());
-    }
-
-    foreach ($xactions as $key => $xaction) {
-      $has_effect = $this->applyTransaction($mock, $xaction);
-      if (!$has_effect) {
-        unset($xactions[$key]);
-      }
-    }
-
-    if (!$xactions) {
-      return;
-    }
-
-    $mock->openTransaction();
-      $mock->save();
-
-      foreach ($xactions as $xaction) {
-        $xaction->setMockID($mock->getID());
-        $xaction->save();
-      }
-
-      // Apply ID/PHID-dependent transactions.
-      foreach ($xactions as $xaction) {
-        $type = $xaction->getTransactionType();
-        switch ($type) {
-          case PholioTransactionType::TYPE_SUBSCRIBERS:
-            $subeditor = id(new PhabricatorSubscriptionsEditor())
-              ->setObject($mock)
-              ->setActor($this->requireActor())
-              ->subscribeExplicit($xaction->getNewValue())
-              ->save();
-            break;
+    switch ($xaction->getTransactionType()) {
+      case PholioTransactionType::TYPE_NAME:
+        $object->setName($xaction->getNewValue());
+        if ($object->getOriginalName() === null) {
+          $object->setOriginalName($xaction->getNewValue());
         }
-      }
-
-    $mock->saveTransaction();
-
-    $this->sendMail($mock, $xactions, $is_new, $mentioned_phids);
-
-    PholioIndexer::indexMock($mock);
-
-    return $this;
+        break;
+      case PholioTransactionType::TYPE_DESCRIPTION:
+        $object->setDescription($xaction->getNewValue());
+        break;
+    }
   }
 
+  protected function applyCustomExternalTransaction(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+    return;
+  }
+
+  protected function mergeTransactions(
+    PhabricatorApplicationTransaction $u,
+    PhabricatorApplicationTransaction $v) {
+
+    $type = $u->getTransactionType();
+    switch ($type) {
+      case PholioTransactionType::TYPE_NAME:
+      case PholioTransactionType::TYPE_DESCRIPTION:
+        return $v;
+    }
+
+    return parent::mergeTransactions($u, $v);
+  }
+
+
   private function sendMail(
     PholioMock $mock,
     array $xactions,
@@ -194,119 +171,5 @@ final class PholioMockEditor extends PhabricatorEditor {
     return PhabricatorEnv::getEnvConfig('metamta.pholio.subject-prefix');
   }
 
-  private function applyTransaction(
-    PholioMock $mock,
-    PholioTransaction $xaction) {
-
-    $type = $xaction->getTransactionType();
-
-    $old = null;
-    switch ($type) {
-      case PholioTransactionType::TYPE_NONE:
-        $old = null;
-        break;
-      case PholioTransactionType::TYPE_NAME:
-        $old = $mock->getName();
-        break;
-      case PholioTransactionType::TYPE_DESCRIPTION:
-        $old = $mock->getDescription();
-        break;
-      case PholioTransactionType::TYPE_VIEW_POLICY:
-        $old = $mock->getViewPolicy();
-        break;
-      case PholioTransactionType::TYPE_SUBSCRIBERS:
-        $old = PhabricatorSubscribersQuery::loadSubscribersForPHID(
-          $mock->getPHID());
-        break;
-      default:
-        throw new Exception("Unknown transaction type '{$type}'!");
-    }
-
-    $xaction->setOldValue($old);
-
-    if (!$this->transactionHasEffect($mock, $xaction)) {
-      return false;
-    }
-
-    switch ($type) {
-      case PholioTransactionType::TYPE_NONE:
-        break;
-      case PholioTransactionType::TYPE_NAME:
-        $mock->setName($xaction->getNewValue());
-        if ($mock->getOriginalName() === null) {
-          $mock->setOriginalName($xaction->getNewValue());
-        }
-        break;
-      case PholioTransactionType::TYPE_DESCRIPTION:
-        $mock->setDescription($xaction->getNewValue());
-        break;
-      case PholioTransactionType::TYPE_VIEW_POLICY:
-        $mock->setViewPolicy($xaction->getNewValue());
-        break;
-      case PholioTransactionType::TYPE_SUBSCRIBERS:
-        // This applies later.
-        break;
-      default:
-        throw new Exception("Unknown transaction type '{$type}'!");
-    }
-
-    return true;
-  }
-
-  private function transactionHasEffect(
-    PholioMock $mock,
-    PholioTransaction $xaction) {
-
-    $effect = false;
-
-    $old = $xaction->getOldValue();
-    $new = $xaction->getNewValue();
-
-    $type = $xaction->getTransactionType();
-    switch ($type) {
-      case PholioTransactionType::TYPE_NONE:
-      case PholioTransactionType::TYPE_NAME:
-      case PholioTransactionType::TYPE_DESCRIPTION:
-      case PholioTransactionType::TYPE_VIEW_POLICY:
-        $effect = ($old !== $new);
-        break;
-      case PholioTransactionType::TYPE_SUBSCRIBERS:
-        $old = nonempty($old, array());
-        $old_map = array_fill_keys($old, true);
-        $filtered = $old;
-
-        foreach ($new as $phid) {
-          if ($mock->getAuthorPHID() == $phid) {
-            // The author may not be explicitly subscribed.
-            continue;
-          }
-          if (isset($old_map[$phid])) {
-            // This PHID was already subscribed.
-            continue;
-          }
-          $filtered[] = $phid;
-        }
-
-        $old = array_keys($old_map);
-        $new = array_values($filtered);
-
-        $xaction->setOldValue($old);
-        $xaction->setNewValue($new);
-
-        $effect = ($old !== $new);
-        break;
-      default:
-        throw new Exception("Unknown transaction type '{$type}'!");
-    }
-
-    if (!$effect) {
-      if (strlen($xaction->getComment())) {
-        $xaction->setTransactionType(PholioTransactionType::TYPE_NONE);
-        $effect = true;
-      }
-    }
-
-    return $effect;
-  }
 
 }
diff --git a/src/applications/pholio/query/PholioTransactionQuery.php b/src/applications/pholio/query/PholioTransactionQuery.php
index 28761bbc83..09194c0fd2 100644
--- a/src/applications/pholio/query/PholioTransactionQuery.php
+++ b/src/applications/pholio/query/PholioTransactionQuery.php
@@ -4,45 +4,10 @@
  * @group pholio
  */
 final class PholioTransactionQuery
-  extends PhabricatorOffsetPagedQuery {
+  extends PhabricatorApplicationTransactionQuery {
 
-  private $mockIDs;
-
-  public function withMockIDs(array $ids) {
-    $this->mockIDs = $ids;
-    return $this;
-  }
-
-  public function execute() {
-    $table = new PholioTransaction();
-    $conn_r = $table->establishConnection('r');
-
-    $data = queryfx_all(
-      $conn_r,
-      'SELECT * FROM %T x %Q %Q %Q',
-      $table->getTableName(),
-      $this->buildWhereClause($conn_r),
-      $this->buildOrderClause($conn_r),
-      $this->buildLimitClause($conn_r));
-
-    return $table->loadAllFromArray($data);
-  }
-
-  private function buildWhereClause(AphrontDatabaseConnection $conn_r) {
-    $where = array();
-
-    if ($this->mockIDs) {
-      $where[] = qsprintf(
-        $conn_r,
-        'mockID IN (%Ld)',
-        $this->mockIDs);
-    }
-
-    return $this->formatWhereClause($where);
-  }
-
-  private function buildOrderClause(AphrontDatabaseConnection $conn_r) {
-    return 'ORDER BY id ASC';
+  protected function getTemplateApplicationTransaction() {
+    return new PholioTransaction();
   }
 
 }
diff --git a/src/applications/pholio/storage/PholioPixelComment.php b/src/applications/pholio/storage/PholioPixelComment.php
deleted file mode 100644
index f7284333a0..0000000000
--- a/src/applications/pholio/storage/PholioPixelComment.php
+++ /dev/null
@@ -1,46 +0,0 @@
-<?php
-
-/**
- * @group pholio
- */
-final class PholioPixelComment extends PholioDAO
-  implements PhabricatorMarkupInterface {
-
-  const MARKUP_FIELD_COMMENT  = 'markup:comment';
-
-  protected $mockID;
-  protected $transactionID;
-  protected $authorPHID;
-  protected $imageID;
-
-  protected $x;
-  protected $y;
-  protected $width;
-  protected $height;
-  protected $comment;
-
-
-/* -(  PhabricatorMarkupInterface  )----------------------------------------- */
-
-
-  public function getMarkupFieldKey($field) {
-    return 'MP:'.$this->getID();
-  }
-
-  public function newMarkupEngine($field) {
-    return PhabricatorMarkupEngine::newMarkupEngine(array());
-  }
-
-  public function getMarkupText($field) {
-    return $this->getComment();
-  }
-
-  public function didMarkupText($field, $output, PhutilMarkupEngine $engine) {
-    return $output;
-  }
-
-  public function shouldUseMarkupCache($field) {
-    return ($this->getID() && $this->getTransactionID());
-  }
-
-}
diff --git a/src/applications/pholio/storage/PholioTransaction.php b/src/applications/pholio/storage/PholioTransaction.php
index 60515ee4ab..55a5ab7ba6 100644
--- a/src/applications/pholio/storage/PholioTransaction.php
+++ b/src/applications/pholio/storage/PholioTransaction.php
@@ -3,104 +3,60 @@
 /**
  * @group pholio
  */
-final class PholioTransaction extends PholioDAO
-  implements PhabricatorMarkupInterface {
+final class PholioTransaction extends PhabricatorApplicationTransaction {
 
-  const MARKUP_FIELD_COMMENT  = 'markup:comment';
-
-  protected $mockID;
-  protected $authorPHID;
-  protected $transactionType;
-  protected $oldValue;
-  protected $newValue;
-  protected $comment = '';
-  protected $metadata = array();
-  protected $contentSource;
-
-  public function getConfiguration() {
-    return array(
-      self::CONFIG_SERIALIZATION => array(
-        'oldValue' => self::SERIALIZATION_JSON,
-        'newValue' => self::SERIALIZATION_JSON,
-        'metadata' => self::SERIALIZATION_JSON,
-      ),
-    ) + parent::getConfiguration();
+  public function getApplicationName() {
+    return 'pholio';
   }
 
-  public function setContentSource(PhabricatorContentSource $content_source) {
-    $this->contentSource = $content_source->serialize();
-    return $this;
+  public function getApplicationTransactionType() {
+    return PhabricatorPHIDConstants::PHID_TYPE_MOCK;
   }
 
-  public function getContentSource() {
-    return PhabricatorContentSource::newFromSerialized($this->contentSource);
+  public function getApplicationTransactionCommentObject() {
+    return new PholioTransactionComment();
   }
 
-  public function getRequiredHandlePHIDs() {
+  public function getApplicationObjectTypeName() {
+    return pht('mock');
+  }
+
+  public function shouldHide() {
+    $old = $this->getOldValue();
+
     switch ($this->getTransactionType()) {
-      case PholioTransactionType::TYPE_SUBSCRIBERS:
-        return array_merge(
-          $this->getOldValue(),
-          $this->getNewValue());
-      default:
-        return array();
+      case PholioTransactionType::TYPE_NAME:
+      case PholioTransactionType::TYPE_DESCRIPTION:
+        return ($old === null);
     }
+
+    return parent::shouldHide();
   }
 
+  public function getTitle() {
+    $author_phid = $this->getAuthorPHID();
 
-/* -(  PhabricatorSubscribableInterface Implementation  )-------------------- */
+    $old = $this->getOldValue();
+    $new = $this->getNewValue();
 
-
-  public function isAutomaticallySubscribed($phid) {
-    return ($this->authorPHID == $phid);
-  }
-
-
-/* -(  PhabricatorPolicyInterface Implementation  )-------------------------- */
-
-
-  public function getCapabilities() {
-    return array(
-      PhabricatorPolicyCapability::CAN_VIEW,
-      PhabricatorPolicyCapability::CAN_EDIT,
-    );
-  }
-
-  public function getPolicy($capability) {
-    switch ($capability) {
-      case PhabricatorPolicyCapability::CAN_VIEW:
-        return $this->getViewPolicy();
-      case PhabricatorPolicyCapability::CAN_EDIT:
-        return PhabricatorPolicies::POLICY_NOONE;
+    switch ($this->getTransactionType()) {
+      case PholioTransactionType::TYPE_NAME:
+        return pht(
+          '%s renamed this mock from "%s" to "%s".',
+          $this->renderHandleLink($author_phid),
+          phutil_escape_html($old),
+          phutil_escape_html($new));
+        break;
+      case PholioTransactionType::TYPE_DESCRIPTION:
+        return pht(
+          '%s updated the description of this mock. '.
+          'The old description was: %s',
+          $this->renderHandleLink($author_phid),
+          phutil_escape_html($old));
     }
+
+    return parent::getTitle();
   }
 
-  public function hasAutomaticCapbility($capability, PhabricatorUser $viewer) {
-    return ($viewer->getPHID() == $this->getAuthorPHID());
-  }
-
-
-/* -(  PhabricatorMarkupInterface  )----------------------------------------- */
-
-
-  public function getMarkupFieldKey($field) {
-    return 'MX:'.$this->getID();
-  }
-
-  public function newMarkupEngine($field) {
-    return PhabricatorMarkupEngine::newMarkupEngine(array());
-  }
-
-  public function getMarkupText($field) {
-    return $this->getComment();
-  }
-
-  public function didMarkupText($field, $output, PhutilMarkupEngine $engine) {
-    return $output;
-  }
-
-  public function shouldUseMarkupCache($field) {
-    return (bool)$this->getID();
-  }
 
 }
diff --git a/src/applications/pholio/storage/PholioTransactionComment.php b/src/applications/pholio/storage/PholioTransactionComment.php
new file mode 100644
index 0000000000..27846e6377
--- /dev/null
+++ b/src/applications/pholio/storage/PholioTransactionComment.php
@@ -0,0 +1,19 @@
+<?php
+
+/**
+ * @group pholio
+ */
+final class PholioTransactionComment
+  extends PhabricatorApplicationTransactionComment {
+
+  protected $imageID;
+  protected $x;
+  protected $y;
+  protected $width;
+  protected $height;
+
+  public function getApplicationTransactionObject() {
+    return new PholioTransaction();
+  }
+
+}
diff --git a/src/applications/transactions/application/PhabricatorApplicationTransactions.php b/src/applications/transactions/application/PhabricatorApplicationTransactions.php
new file mode 100644
index 0000000000..8c7e7a2c82
--- /dev/null
+++ b/src/applications/transactions/application/PhabricatorApplicationTransactions.php
@@ -0,0 +1,15 @@
+<?php
+
+final class PhabricatorApplicationTransactions extends PhabricatorApplication {
+
+  public function shouldAppearInLaunchView() {
+    return false;
+  }
+
+  public function getRoutes() {
+    return array(
+    );
+  }
+
+}
+
diff --git a/src/applications/transactions/constants/PhabricatorTransactions.php b/src/applications/transactions/constants/PhabricatorTransactions.php
new file mode 100644
index 0000000000..54140c3f7c
--- /dev/null
+++ b/src/applications/transactions/constants/PhabricatorTransactions.php
@@ -0,0 +1,10 @@
+<?php
+
+final class PhabricatorTransactions {
+
+  const TYPE_COMMENT      = 'core:comment';
+  const TYPE_SUBSCRIBERS  = 'core:subscribers';
+  const TYPE_VIEW_POLICY  = 'core:view-policy';
+  const TYPE_EDIT_POLICY  = 'core:edit-policy';
+
+}
diff --git a/src/applications/transactions/editor/PhabricatorApplicationTransactionCommentEditor.php b/src/applications/transactions/editor/PhabricatorApplicationTransactionCommentEditor.php
new file mode 100644
index 0000000000..fe0680a121
--- /dev/null
+++ b/src/applications/transactions/editor/PhabricatorApplicationTransactionCommentEditor.php
@@ -0,0 +1,102 @@
+<?php
+
+final class PhabricatorApplicationTransactionCommentEditor
+  extends PhabricatorEditor {
+
+  private $contentSource;
+
+  public function setContentSource(PhabricatorContentSource $content_source) {
+    $this->contentSource = $content_source;
+    return $this;
+  }
+
+  public function getContentSource() {
+    return $this->contentSource;
+  }
+
+  /**
+   * Edit a transaction's comment. This method effects the required create,
+   * update or delete to set the transaction's comment to the provided comment.
+   */
+  public function applyEdit(
+    PhabricatorApplicationTransaction $xaction,
+    PhabricatorApplicationTransactionComment $comment) {
+
+    $this->validateEdit($xaction, $comment);
+
+    $actor = $this->requireActor();
+
+    $comment->setContentSource($this->getContentSource());
+    $comment->setAuthorPHID($actor->getPHID());
+
+    // TODO: This needs to be more sophisticated once we have meta-policies.
+    $comment->setViewPolicy(PhabricatorPolicies::POLICY_PUBLIC);
+    $comment->setEditPolicy($actor->getPHID());
+
+    $xaction->openTransaction();
+      $xaction->beginReadLocking();
+        if ($xaction->getID()) {
+          $xaction->reload();
+        }
+
+        $new_version = $xaction->getCommentVersion() + 1;
+
+        $comment->setCommentVersion($new_version);
+        $comment->setTransactionPHID($xaction->getPHID());
+        $comment->save();
+
+        $xaction->setCommentVersion($new_version);
+        $xaction->setCommentPHID($comment->getPHID());
+        $xaction->setViewPolicy($comment->getViewPolicy());
+        $xaction->setEditPolicy($comment->getEditPolicy());
+        $xaction->save();
+
+      $xaction->endReadLocking();
+    $xaction->saveTransaction();
+
+    $xaction->attachComment($comment);
+
+    // TODO: Emit an event for notifications/feed? Can we handle them
+    // generically?
+
+    return $this;
+  }
+
+  /**
+   * Validate that the edit is permissible, and the actor has permission to
+   * perform it.
+   */
+  private function validateEdit(
+    PhabricatorApplicationTransaction $xaction,
+    PhabricatorApplicationTransactionComment $comment) {
+
+    if (!$xaction->getPHID()) {
+      throw new Exception(
+        "Transaction must have a PHID before calling applyEdit()!");
+    }
+
+    if ($comment->getPHID()) {
+      throw new Exception(
+        "Transaction comment must not yet have a PHID!");
+    }
+
+    if (!$this->getContentSource()) {
+      throw new Exception(
+        "Call setContentSource() before applyEdit()!");
+    }
+
+    $actor = $this->requireActor();
+
+    PhabricatorPolicyFilter::requireCapability(
+      $actor,
+      $xaction,
+      PhabricatorPolicyCapability::CAN_VIEW);
+
+    PhabricatorPolicyFilter::requireCapability(
+      $actor,
+      $xaction,
+      PhabricatorPolicyCapability::CAN_EDIT);
+  }
+
+
+}
diff --git a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
new file mode 100644
index 0000000000..1b8c8d3d6e
--- /dev/null
+++ b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
@@ -0,0 +1,487 @@
+<?php
+
+abstract class PhabricatorApplicationTransactionEditor
+  extends PhabricatorEditor {
+
+  private $contentSource;
+  private $object;
+  private $xactions;
+
+  private $isNewObject;
+  private $mentionedPHIDs;
+
+  protected function getIsNewObject() {
+    return $this->isNewObject;
+  }
+
+  protected function getMentionedPHIDs() {
+    return $this->mentionedPHIDs;
+  }
+
+  public function getTransactionTypes() {
+    $types = array(
+      PhabricatorTransactions::TYPE_COMMENT,
+    );
+
+    if ($this->object instanceof PhabricatorSubscribableInterface) {
+      $types[] = PhabricatorTransactions::TYPE_SUBSCRIBERS;
+    }
+
+    return $types;
+  }
+
+  private function adjustTransactionValues(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+    $old = $this->getTransactionOldValue($object, $xaction);
+    $xaction->setOldValue($old);
+
+    $new = $this->getTransactionNewValue($object, $xaction);
+    $xaction->setNewValue($new);
+  }
+
+  private function getTransactionOldValue(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+    switch ($xaction->getTransactionType()) {
+      case PhabricatorTransactions::TYPE_SUBSCRIBERS:
+        if ($object->getPHID()) {
+          $old_phids = PhabricatorSubscribersQuery::loadSubscribersForPHID(
+            $object->getPHID());
+        } else {
+          $old_phids = array();
+        }
+        return array_values($old_phids);
+      case PhabricatorTransactions::TYPE_VIEW_POLICY:
+        return $object->getViewPolicy();
+      case PhabricatorTransactions::TYPE_EDIT_POLICY:
+        return $object->getEditPolicy();
+      default:
+        return $this->getCustomTransactionOldValue($object, $xaction);
+    }
+  }
+
+  private function getTransactionNewValue(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+    switch ($xaction->getTransactionType()) {
+      case PhabricatorTransactions::TYPE_SUBSCRIBERS:
+        return $this->getPHIDTransactionNewValue($xaction);
+      case PhabricatorTransactions::TYPE_VIEW_POLICY:
+      case PhabricatorTransactions::TYPE_EDIT_POLICY:
+        return $xaction->getNewValue();
+      default:
+        return $this->getCustomTransactionNewValue($object, $xaction);
+    }
+  }
+
+  protected function getCustomTransactionOldValue(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+    throw new Exception("Capability not supported!");
+  }
+
+  protected function getCustomTransactionNewValue(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+    throw new Exception("Capability not supported!");
+  }
+
+  protected function transactionHasEffect(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+    return ($xaction->getOldValue() !== $xaction->getNewValue());
+  }
+
+  private function applyInternalEffects(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+    switch ($xaction->getTransactionType()) {
+      case PhabricatorTransactions::TYPE_COMMENT:
+        break;
+      case PhabricatorTransactions::TYPE_VIEW_POLICY:
+        $object->setViewPolicy($xaction->getNewValue());
+        break;
+      case PhabricatorTransactions::TYPE_EDIT_POLICY:
+        $object->setEditPolicy($xaction->getNewValue());
+        break;
+      default:
+        return $this->applyCustomInternalTransaction($object, $xaction);
+    }
+  }
+
+  private function applyExternalEffects(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+    switch ($xaction->getTransactionType()) {
+      case PhabricatorTransactions::TYPE_COMMENT:
+        break;
+      case PhabricatorTransactions::TYPE_SUBSCRIBERS:
+        $subeditor = id(new PhabricatorSubscriptionsEditor())
+          ->setObject($object)
+          ->setActor($this->requireActor())
+          ->subscribeExplicit($xaction->getNewValue())
+          ->save();
+        break;
+      default:
+        return $this->applyCustomExternalTransaction($object, $xaction);
+    }
+  }
+
+  protected function applyCustomInternalTransaction(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+    throw new Exception("Capability not supported!");
+  }
+
+  protected function applyCustomExternalTransaction(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+    throw new Exception("Capability not supported!");
+  }
+
+  public function setContentSource(PhabricatorContentSource $content_source) {
+    $this->contentSource = $content_source;
+    return $this;
+  }
+
+  public function getContentSource() {
+    return $this->contentSource;
+  }
+
+  protected function didApplyTransactions(
+    PhabricatorLiskDAO $object,
+    array $xactions) {
+    return;
+  }
+
+  final public function applyTransactions(
+    PhabricatorLiskDAO $object,
+    array $xactions) {
+
+    $this->object = $object;
+    $this->xactions = $xactions;
+    $this->isNewObject = ($object->getPHID() === null);
+
+    $this->validateEditParameters($object, $xactions);
+
+
+    $actor = $this->requireActor();
+
+    $mention_xaction = $this->buildMentionTransaction($object, $xactions);
+    if ($mention_xaction) {
+      $xactions[] = $mention_xaction;
+    }
+
+    $xactions = $this->combineTransactions($xactions);
+
+    foreach ($xactions as $xaction) {
+      // TODO: This needs to be more sophisticated once we have meta-policies.
+      $xaction->setViewPolicy(PhabricatorPolicies::POLICY_PUBLIC);
+      $xaction->setEditPolicy($actor->getPHID());
+
+      $xaction->setAuthorPHID($actor->getPHID());
+      $xaction->setContentSource($this->getContentSource());
+    }
+
+    foreach ($xactions as $xaction) {
+      $this->adjustTransactionValues($object, $xaction);
+    }
+
+    foreach ($xactions as $key => $xaction) {
+      if (!$this->transactionHasEffect($object, $xaction)) {
+        // TODO: Raise these to the user.
+        if ($xaction->getComment()) {
+          $xaction->setTransactionType(
+            PhabricatorTransactions::TYPE_COMMENT);
+          $xaction->setOldValue(null);
+          $xaction->setNewValue(null);
+        } else {
+          unset($xactions[$key]);
+        }
+      }
+    }
+
+    $xactions = $this->sortTransactions($xactions);
+
+    $comment_editor = id(new PhabricatorApplicationTransactionCommentEditor())
+      ->setActor($actor)
+      ->setContentSource($this->getContentSource());
+
+    $object->openTransaction();
+      foreach ($xactions as $xaction) {
+        $this->applyInternalEffects($object, $xaction);
+      }
+
+      $object->save();
+
+      foreach ($xactions as $xaction) {
+        $xaction->setObjectPHID($object->getPHID());
+        if ($xaction->getComment()) {
+          $xaction->setPHID($xaction->generatePHID());
+          $comment_editor->applyEdit($xaction, $xaction->getComment());
+        } else {
+          $xaction->save();
+        }
+      }
+
+      foreach ($xactions as $xaction) {
+        $this->applyExternalEffects($object, $xaction);
+      }
+    $object->saveTransaction();
+
+    // TODO: Send mail.
+    // TODO: Index object.
+    // TODO: Publish feed/notifications.
+
+    $this->didApplyTransactions($object, $xactions);
+
+    return $this;
+  }
+
+  private function validateEditParameters(
+    PhabricatorLiskDAO $object,
+    array $xactions) {
+
+    if (!$this->getContentSource()) {
+      throw new Exception(
+        "Call setContentSource() before applyTransactions()!");
+    }
+
+    // Do a bunch of sanity checks that the incoming transactions are fresh.
+    // They should be unsaved and have only "transactionType" and "newValue"
+    // set.
+
+    $types = array_fill_keys($this->getTransactionTypes(), true);
+
+    assert_instances_of($xactions, 'PhabricatorApplicationTransaction');
+    foreach ($xactions as $xaction) {
+      if ($xaction->getPHID() || $xaction->getID()) {
+        throw new Exception(
+          "You can not apply transactions which already have IDs/PHIDs!");
+      }
+      if ($xaction->getObjectPHID()) {
+        throw new Exception(
+          "You can not apply transactions which already have objectPHIDs!");
+      }
+      if ($xaction->getAuthorPHID()) {
+        throw new Exception(
+          "You can not apply transactions which already have authorPHIDs!");
+      }
+      if ($xaction->getCommentPHID()) {
+        throw new Exception(
+          "You can not apply transactions which already have commentPHIDs!");
+      }
+      if ($xaction->getCommentVersion() !== 0) {
+        throw new Exception(
+          "You can not apply transactions which already have commentVersions!");
+      }
+      if ($xaction->getOldValue() !== null) {
+        throw new Exception(
+          "You can not apply transactions which already have oldValue!");
+      }
+
+      $type = $xaction->getTransactionType();
+      if (empty($types[$type])) {
+        throw new Exception("Transaction has unknown type '{$type}'.");
+      }
+    }
+
+    // The actor must have permission to view and edit the object.
+
+    $actor = $this->requireActor();
+
+    PhabricatorPolicyFilter::requireCapability(
+      $actor,
+      $xaction,
+      PhabricatorPolicyCapability::CAN_VIEW);
+
+    PhabricatorPolicyFilter::requireCapability(
+      $actor,
+      $xaction,
+      PhabricatorPolicyCapability::CAN_EDIT);
+  }
+
+  private function buildMentionTransaction(
+    PhabricatorLiskDAO $object,
+    array $xactions) {
+
+    if (!($object instanceof PhabricatorSubscribableInterface)) {
+      return null;
+    }
+
+    $texts = array();
+    foreach ($xactions as $xaction) {
+      $texts[] = $this->getMentionableTextsFromTransaction($xaction);
+    }
+    $texts = array_mergev($texts);
+
+    $phids = PhabricatorMarkupEngine::extractPHIDsFromMentions($texts);
+
+    $this->mentionedPHIDs = $phids;
+
+    if (!$phids) {
+      return null;
+    }
+
+    $xaction = newv(get_class(head($xactions)), array());
+    $xaction->setTransactionType(PhabricatorTransactions::TYPE_SUBSCRIBERS);
+    $xaction->setNewValue(array('+' => $phids));
+
+    return $xaction;
+  }
+
+  protected function getMentionableTextsFromTransaction(
+    PhabricatorApplicationTransaction $transaction) {
+    $texts = array();
+    if ($transaction->getComment()) {
+      $texts[] = $transaction->getComment()->getContent();
+    }
+    return $texts;
+  }
+
+  protected function mergeTransactions(
+    PhabricatorApplicationTransaction $u,
+    PhabricatorApplicationTransaction $v) {
+
+    $type = $u->getTransactionType();
+
+    switch ($type) {
+      case PhabricatorTransactions::TYPE_SUBSCRIBERS:
+        return $this->mergePHIDTransactions($u, $v);
+    }
+
+    // By default, do not merge the transactions.
+    return null;
+  }
+
+
+  /**
+   * Attempt to combine similar transactions into a smaller number of total
+   * transactions. For example, two transactions which edit the title of an
+   * object can be merged into a single edit.
+   */
+  private function combineTransactions(array $xactions) {
+    $stray_comments = array();
+
+    $result = array();
+    $types = array();
+    foreach ($xactions as $key => $xaction) {
+      $type = $xaction->getTransactionType();
+      if (isset($types[$type])) {
+        foreach ($types[$type] as $other_key) {
+          $merged = $this->mergeTransactions($result[$other_key], $xaction);
+          if ($merged) {
+            $result[$other_key] = $merged;
+
+            if ($xaction->getComment() &&
+                ($xaction->getComment() !== $merged->getComment())) {
+              $stray_comments[] = $xaction->getComment();
+            }
+
+            if ($result[$other_key]->getComment() &&
+                ($result[$other_key]->getComment() !== $merged->getComment())) {
+              $stray_comments[] = $result[$other_key]->getComment();
+            }
+
+            // Move on to the next transaction.
+            continue 2;
+          }
+        }
+      }
+      $result[$key] = $xaction;
+      $types[$type][] = $key;
+    }
+
+    // If we merged any comments away, restore them.
+    foreach ($stray_comments as $comment) {
+      $xaction = newv(get_class(head($result)), array());
+      $xaction->setTransactionType(PhabricatorTransactions::TYPE_COMMENT);
+      $xaction->setComment($comment);
+      $result[] = $xaction;
+    }
+
+    return array_values($result);
+  }
+
+  protected function mergePHIDTransactions(
+    PhabricatorApplicationTransaction $u,
+    PhabricatorApplicationTransaction $v) {
+
+    $result = $u->getNewValue();
+    foreach ($v->getNewValue() as $key => $value) {
+      $result[$key] = array_merge($value, idx($result, $key, array()));
+    }
+    $u->setNewValue($result);
+
+    return $u;
+  }
+
+
+  protected function getPHIDTransactionNewValue(
+    PhabricatorApplicationTransaction $xaction) {
+
+    $old = array_combine($xaction->getOldValue(), $xaction->getOldValue());
+
+    $new = $xaction->getNewValue();
+    $new_add = idx($new, '+', array());
+    unset($new['+']);
+    $new_rem = idx($new, '-', array());
+    unset($new['-']);
+    $new_set = idx($new, '=', null);
+    if ($new_set !== null) {
+      $new_set = array_combine($new_set, $new_set);
+    }
+    unset($new['=']);
+
+    if ($new) {
+      throw new Exception(
+        "Invalid 'new' value for PHID transaction. Value should contain only ".
+        "keys '+' (add PHIDs), '-' (remove PHIDs) and '=' (set PHIDS).");
+    }
+
+    $result = array();
+
+    foreach ($old as $phid) {
+      if ($new_set !== null && empty($new_set[$phid])) {
+        continue;
+      }
+      $result[$phid] = $phid;
+    }
+
+    if ($new_set !== null) {
+      foreach ($new_set as $phid) {
+        $result[$phid] = $phid;
+      }
+    }
+
+    foreach ($new_add as $phid) {
+      $result[$phid] = $phid;
+    }
+
+    foreach ($new_rem as $phid) {
+      unset($result[$phid]);
+    }
+
+    return array_values($result);
+  }
+
+  protected function sortTransactions(array $xactions) {
+    $head = array();
+    $tail = array();
+
+    // Move bare comments to the end, so the actions preceed them.
+    foreach ($xactions as $xaction) {
+      $type = $xaction->getTransactionType();
+      if ($type == PhabricatorTransactions::TYPE_COMMENT) {
+        $tail[] = $xaction;
+      } else {
+        $head[] = $xaction;
+      }
+    }
+
+    return array_values(array_merge($head, $tail));
+  }
+
+
+}
diff --git a/src/applications/transactions/query/PhabricatorApplicationTransactionCommentQuery.php b/src/applications/transactions/query/PhabricatorApplicationTransactionCommentQuery.php
new file mode 100644
index 0000000000..2744189115
--- /dev/null
+++ b/src/applications/transactions/query/PhabricatorApplicationTransactionCommentQuery.php
@@ -0,0 +1,62 @@
+<?php
+
+final class PhabricatorApplicationTransactionCommentQuery
+  extends PhabricatorCursorPagedPolicyAwareQuery {
+
+  private $template;
+
+  private $phids;
+  private $transactionPHIDs;
+
+  public function setTemplate(
+    PhabricatorApplicationTransactionComment $template) {
+    $this->template = $template;
+    return $this;
+  }
+
+  public function withPHIDs(array $phids) {
+    $this->phids = $phids;
+    return $this;
+  }
+
+  public function withTranactionPHIDs(array $transaction_phids) {
+    $this->transactionPHIDs = $transaction_phids;
+    return $this;
+  }
+
+  public function loadPage() {
+    $table = $this->template;
+    $conn_r = $table->establishConnection('r');
+
+    $data = queryfx_all(
+      $conn_r,
+      'SELECT * FROM %T xc %Q %Q %Q',
+      $table->getTableName(),
+      $this->buildWhereClause($conn_r),
+      $this->buildOrderClause($conn_r),
+      $this->buildLimitClause($conn_r));
+
+    return $table->loadAllFromArray($data);
+  }
+
+  private function buildWhereClause(AphrontDatabaseConnection $conn_r) {
+    $where = array();
+
+    if ($this->phids) {
+      $where[] = qsprintf(
+        $conn_r,
+        'phid IN (%Ls)',
+        $this->phids);
+    }
+
+    if ($this->transactionPHIDs) {
+      $where[] = qsprintf(
+        $conn_r,
+        'transactionPHID IN (%Ls)',
+        $this->transactionPHIDs);
+    }
+
+    return $this->formatWhereClause($where);
+  }
+
+}
diff --git a/src/applications/transactions/query/PhabricatorApplicationTransactionQuery.php b/src/applications/transactions/query/PhabricatorApplicationTransactionQuery.php
new file mode 100644
index 0000000000..f49e37c8c1
--- /dev/null
+++ b/src/applications/transactions/query/PhabricatorApplicationTransactionQuery.php
@@ -0,0 +1,143 @@
+<?php
+
+abstract class PhabricatorApplicationTransactionQuery
+  extends PhabricatorCursorPagedPolicyAwareQuery {
+
+  private $phids;
+  private $objectPHIDs;
+  private $authorPHIDs;
+
+  private $needComments = true;
+  private $needHandles  = true;
+
+  abstract protected function getTemplateApplicationTransaction();
+
+  protected function buildMoreWhereClauses(AphrontDatabaseConnection $conn_r) {
+    return array();
+  }
+
+  protected function getReversePaging() {
+    return true;
+  }
+
+  public function withPHIDs(array $phids) {
+    $this->phids = $phids;
+    return $this;
+  }
+
+  public function withObjectPHIDs(array $object_phids) {
+    $this->objectPHIDs = $object_phids;
+    return $this;
+  }
+
+  public function withAuthorPHIDs(array $author_phids) {
+    $this->authorPHIDs = $author_phids;
+    return $this;
+  }
+
+  public function needComments($need) {
+    $this->needComments = $need;
+    return $this;
+  }
+
+  public function needHandles($need) {
+    $this->needHandles = $need;
+    return $this;
+  }
+
+  public function loadPage() {
+    $table = $this->getTemplateApplicationTransaction();
+    $conn_r = $table->establishConnection('r');
+
+    $data = queryfx_all(
+      $conn_r,
+      'SELECT * FROM %T x %Q %Q %Q',
+      $table->getTableName(),
+      $this->buildWhereClause($conn_r),
+      $this->buildOrderClause($conn_r),
+      $this->buildLimitClause($conn_r));
+
+    $xactions = $table->loadAllFromArray($data);
+
+    if ($this->needComments) {
+      $comment_phids = array_filter(mpull($xactions, 'getCommentPHID'));
+
+      $comments = array();
+      if ($comment_phids) {
+        $comments = id(new PhabricatorApplicationTransactionCommentQuery())
+          ->setTemplate($table->getApplicationTransactionCommentObject())
+          ->setViewer($this->getViewer())
+          ->withPHIDs($comment_phids)
+          ->execute();
+        $comments = mpull($comments, null, 'getPHID');
+      }
+
+      foreach ($xactions as $xaction) {
+        if ($xaction->getCommentPHID()) {
+          $comment = idx($comments, $xaction->getCommentPHID());
+          if ($comment) {
+            $xaction->attachComment($comment);
+          }
+        }
+      }
+    } else {
+      foreach ($xactions as $xaction) {
+        $xaction->setCommentNotLoaded(true);
+      }
+    }
+
+    if ($this->needHandles) {
+      $phids = array();
+      foreach ($xactions as $xaction) {
+        $phids[$xaction->getPHID()] = $xaction->getRequiredHandlePHIDs();
+      }
+      $handles = array();
+      $merged = array_mergev($phids);
+      if ($merged) {
+        $handles = id(new PhabricatorObjectHandleData($merged))
+          ->setViewer($this->getViewer())
+          ->loadHandles();
+      }
+      foreach ($xactions as $xaction) {
+        $xaction->setHandles(
+          array_select_keys(
+            $handles,
+            $phids[$xaction->getPHID()]));
+      }
+    }
+
+    return $xactions;
+  }
+
+  private function buildWhereClause(AphrontDatabaseConnection $conn_r) {
+    $where = array();
+
+    if ($this->phids) {
+      $where[] = qsprintf(
+        $conn_r,
+        'phid IN (%Ls)',
+        $this->phids);
+    }
+
+    if ($this->objectPHIDs) {
+      $where[] = qsprintf(
+        $conn_r,
+        'objectPHID IN (%Ls)',
+        $this->objectPHIDs);
+    }
+
+    if ($this->authorPHIDs) {
+      $where[] = qsprintf(
+        $conn_r,
+        'authorPHID IN (%Ls)',
+        $this->authorPHIDs);
+    }
+
+    foreach ($this->buildMoreWhereClauses($conn_r) as $clause) {
+      $where[] = $clause;
+    }
+
+    return $this->formatWhereClause($where);
+  }
+
+}
diff --git a/src/applications/transactions/storage/PhabricatorApplicationTransaction.php b/src/applications/transactions/storage/PhabricatorApplicationTransaction.php
new file mode 100644
index 0000000000..c97f6c3839
--- /dev/null
+++ b/src/applications/transactions/storage/PhabricatorApplicationTransaction.php
@@ -0,0 +1,222 @@
+<?php
+
+abstract class PhabricatorApplicationTransaction
+  extends PhabricatorLiskDAO
+  implements PhabricatorPolicyInterface{
+
+  const MARKUP_FIELD_COMMENT  = 'markup:comment';
+
+  protected $phid;
+  protected $objectPHID;
+  protected $authorPHID;
+  protected $viewPolicy;
+  protected $editPolicy;
+
+  protected $commentPHID;
+  protected $commentVersion = 0;
+
+  protected $transactionType;
+  protected $oldValue;
+  protected $newValue;
+
+  protected $contentSource;
+
+  private $comment;
+  private $commentNotLoaded;
+
+  private $handles;
+
+  abstract public function getApplicationTransactionType();
+  abstract public function getApplicationTransactionCommentObject();
+  abstract public function getApplicationObjectTypeName();
+
+  public function generatePHID() {
+    $type = PhabricatorPHIDConstants::PHID_TYPE_XACT;
+    $subtype = $this->getApplicationTransactionType();
+
+    return PhabricatorPHID::generateNewPHID($type, $subtype);
+  }
+
+  public function getConfiguration() {
+    return array(
+      self::CONFIG_AUX_PHID => true,
+      self::CONFIG_SERIALIZATION => array(
+        'oldValue' => self::SERIALIZATION_JSON,
+        'newValue' => self::SERIALIZATION_JSON,
+      ),
+    ) + parent::getConfiguration();
+  }
+
+  public function setContentSource(PhabricatorContentSource $content_source) {
+    $this->contentSource = $content_source->serialize();
+    return $this;
+  }
+
+  public function getContentSource() {
+    return PhabricatorContentSource::newFromSerialized($this->contentSource);
+  }
+
+  public function getComment() {
+    if ($this->commentNotLoaded) {
+      throw new Exception("Comment for this transaction was not loaded.");
+    }
+    return $this->comment;
+  }
+
+  public function attachComment(
+    PhabricatorApplicationTransactionComment $comment) {
+    $this->comment = $comment;
+    $this->commentNotLoaded = false;
+    return $this;
+  }
+
+  public function setCommentNotLoaded($not_loaded) {
+    $this->commentNotLoaded = $not_loaded;
+    return $this;
+  }
+
+/* -(  Rendering  )---------------------------------------------------------- */
+
+  public function getRequiredHandlePHIDs() {
+    $phids = array();
+
+    $old = $this->getOldValue();
+    $new = $this->getNewValue();
+
+    $phids[] = array($this->getAuthorPHID());
+    switch ($this->getTransactionType()) {
+      case PhabricatorTransactions::TYPE_SUBSCRIBERS:
+        $phids[] = $old;
+        $phids[] = $new;
+        break;
+    }
+
+    return array_mergev($phids);
+  }
+
+  public function setHandles(array $handles) {
+    $this->handles = $handles;
+    return $this;
+  }
+
+  public function getHandle($phid) {
+    if (empty($this->handles[$phid])) {
+      throw new Exception(
+        "Transaction requires a handle ('{$phid}') it did not load.");
+    }
+    return $this->handles[$phid];
+  }
+
+  protected function renderHandleLink($phid) {
+    return $this->getHandle($phid)->renderLink();
+  }
+
+  protected function renderHandleList(array $phids) {
+    $links = array();
+    foreach ($phids as $phid) {
+      $links[] = $this->renderHandleLink($phid);
+    }
+    return implode(', ', $links);
+  }
+
+  public function shouldHide() {
+    switch ($this->getTransactionType()) {
+      case PhabricatorTransactions::TYPE_VIEW_POLICY:
+      case PhabricatorTransactions::TYPE_EDIT_POLICY:
+        if ($this->getOldValue() === null) {
+          return true;
+        } else {
+          return false;
+        }
+        break;
+    }
+
+    return false;
+  }
+
+  public function getTitle() {
+    $author_phid = $this->getAuthorPHID();
+
+    $old = $this->getOldValue();
+    $new = $this->getNewValue();
+
+    switch ($this->getTransactionType()) {
+      case PhabricatorTransactions::TYPE_COMMENT:
+        return pht(
+          '%s added a comment.',
+          $this->renderHandleLink($author_phid));
+      case PhabricatorTransactions::TYPE_VIEW_POLICY:
+        // TODO: Render human-readable.
+        return pht(
+          '%s changed the visibility of this %s from "%s" to "%s".',
+          $this->renderHandleLink($author_phid),
+          $this->getApplicationObjectTypeName(),
+          phutil_escape_html($old),
+          phutil_escape_html($new));
+      case PhabricatorTransactions::TYPE_EDIT_POLICY:
+        // TODO: Render human-readable.
+        return pht(
+          '%s changed the edit policy of this %s from "%s" to "%s".',
+          $this->renderHandleLink($author_phid),
+          $this->getApplicationObjectTypeName(),
+          phutil_escape_html($old),
+          phutil_escape_html($new));
+      case PhabricatorTransactions::TYPE_SUBSCRIBERS:
+        $add = array_diff($new, $old);
+        $rem = array_diff($old, $new);
+
+        if ($add && $rem) {
+          return pht(
+            '%s edited subscriber(s), added %d: %s; removed %d: %s.',
+            $this->renderHandleLink($author_phid),
+            count($add),
+            $this->renderHandleList($add),
+            count($rem),
+            $this->renderHandleList($rem));
+        } else if ($add) {
+          return pht(
+            '%s added %d subscriber(s): %s.',
+            $this->renderHandleLink($author_phid),
+            count($add),
+            $this->renderHandleList($add));
+        } else {
+          return pht(
+            '%s removed %d subscribers: %s.',
+            $this->renderHandleLink($author_phid),
+            count($rem),
+            $this->renderHandleList($rem));
+        }
+        break;
+      default:
+        return pht(
+          '%s edited this %s.',
+          $this->renderHandleLink($author_phid),
+          $this->getApplicationObjectTypeName());
+    }
+  }
+
+
+/* -(  PhabricatorPolicyInterface Implementation  )-------------------------- */
+
+
+  public function getCapabilities() {
+    return array(
+      PhabricatorPolicyCapability::CAN_VIEW,
+      PhabricatorPolicyCapability::CAN_EDIT,
+    );
+  }
+
+  public function getPolicy($capability) {
+    switch ($capability) {
+      case PhabricatorPolicyCapability::CAN_VIEW:
+        return $this->getViewPolicy();
+      case PhabricatorPolicyCapability::CAN_EDIT:
+        return $this->getEditPolicy();
+    }
+  }
+
+  public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
+    return ($viewer->getPHID() == $this->getAuthorPHID());
+  }
+
+}
diff --git a/src/applications/transactions/storage/PhabricatorApplicationTransactionComment.php b/src/applications/transactions/storage/PhabricatorApplicationTransactionComment.php
new file mode 100644
index 0000000000..7ca928f85b
--- /dev/null
+++ b/src/applications/transactions/storage/PhabricatorApplicationTransactionComment.php
@@ -0,0 +1,103 @@
+<?php
+
+abstract class PhabricatorApplicationTransactionComment
+  extends PhabricatorLiskDAO
+  implements PhabricatorMarkupInterface, PhabricatorPolicyInterface {
+
+  protected $transactionPHID;
+  protected $commentVersion;
+  protected $authorPHID;
+  protected $viewPolicy;
+  protected $editPolicy;
+  protected $content;
+  protected $contentSource;
+  protected $isDeleted = 0;
+
+  abstract public function getApplicationTransactionObject();
+
+  public function generatePHID() {
+    return PhabricatorPHID::generateNewPHID(
+      PhabricatorPHIDConstants::PHID_TYPE_XCMT);
+  }
+
+  public function getConfiguration() {
+    return array(
+      self::CONFIG_AUX_PHID => true,
+    ) + parent::getConfiguration();
+  }
+
+  public function getApplicationName() {
+    return $this->getApplicationTransactionObject()->getApplicationName();
+  }
+
+  public function getTableName() {
+    $xaction = $this->getApplicationTransactionObject();
+    return self::getTableNameFromTransaction($xaction);
+  }
+
+  public static function getTableNameFromTransaction(
+    PhabricatorApplicationTransaction $xaction) {
+    return $xaction->getTableName().'_comment';
+  }
+
+  public function setContentSource(PhabricatorContentSource $content_source) {
+    $this->contentSource = $content_source->serialize();
+    return $this;
+  }
+
+  public function getContentSource() {
+    return PhabricatorContentSource::newFromSerialized($this->contentSource);
+  }
+
+
+/* -(  PhabricatorMarkupInterface  )----------------------------------------- */
+
+
+  public function getMarkupFieldKey($field) {
+    return PhabricatorPHIDConstants::PHID_TYPE_XCMT.':'.$this->getPHID();
+  }
+
+
+  public function newMarkupEngine($field) {
+    return PhabricatorMarkupEngine::newMarkupEngine(array());
+  }
+
+
+  public function getMarkupText($field) {
+    return $this->getContent();
+  }
+
+
+  public function didMarkupText($field, $output, PhutilMarkupEngine $engine) {
+    return $output;
+  }
+
+
+  public function shouldUseMarkupCache($field) {
+    return (bool)$this->getPHID();
+  }
+
+/* -(  PhabricatorPolicyInterface Implementation  )-------------------------- */
+
+
+  public function getCapabilities() {
+    return array(
+      PhabricatorPolicyCapability::CAN_VIEW,
+      PhabricatorPolicyCapability::CAN_EDIT,
+    );
+  }
+
+  public function getPolicy($capability) {
+    switch ($capability) {
+      case PhabricatorPolicyCapability::CAN_VIEW:
+        return $this->getViewPolicy();
+      case PhabricatorPolicyCapability::CAN_EDIT:
+        return $this->getEditPolicy();
+    }
+  }
+
+  public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
+    return ($viewer->getPHID() == $this->getAuthorPHID());
+  }
+
+}
diff --git a/src/infrastructure/storage/patch/PhabricatorBuiltinPatchList.php b/src/infrastructure/storage/patch/PhabricatorBuiltinPatchList.php
index 44df8a6061..4f82e93d06 100644
--- a/src/infrastructure/storage/patch/PhabricatorBuiltinPatchList.php
+++ b/src/infrastructure/storage/patch/PhabricatorBuiltinPatchList.php
@@ -1044,6 +1044,10 @@ final class PhabricatorBuiltinPatchList extends PhabricatorSQLPatchList {
         'type'    => 'sql',
         'name'    => $this->getPatchPath('owners-exclude.sql'),
       ),
+      '20121209.pholioxactions.sql' => array(
+        'type'    => 'sql',
+        'name'    => $this->getPatchPath('20121209.pholioxactions.sql'),
+      ),
     );
   }