diff --git a/conf/default.conf.php b/conf/default.conf.php
index 00adb39311..ee80b79c30 100644
--- a/conf/default.conf.php
+++ b/conf/default.conf.php
@@ -486,4 +486,23 @@ return array(
 
   'pygments.dropdown-default' => 'infer',
 
+  // This is an override list of regular expressions which allows you to choose
+  // what language files are highlighted as. If your projects have certain rules
+  // about filenames or use unusual or ambiguous language extensions, you can
+  // create a mapping here. This is an ordered dictionary of regular expressions
+  // which will be tested against the filename. They should map to either an
+  // explicit language as a string value, or a numeric index into the captured
+  // groups as an integer.
+  'syntax.filemap' => array(
+    // Example: Treat all '*.xyz' files as PHP.
+    // '@\\.xyz$@' => 'php',
+
+    // Example: Treat 'httpd.conf' as 'apacheconf'.
+    // '@/httpd\\.conf$@' => 'apacheconf',
+
+    // Example: Treat all '*.x.bak' file as '.x'. NOTE: we map to capturing
+    // group 1 by specifying the mapping as "1".
+    // '@\\.([^.]+)\\.bak$@' => 1,
+  ),
+
 );
diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
index f38452557b..f2019e64c1 100644
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -511,6 +511,7 @@ phutil_register_library_map(array(
     'PhabricatorSetup' => 'infrastructure/setup',
     'PhabricatorStandardPageView' => 'view/page/standard',
     'PhabricatorStatusController' => 'applications/status/base',
+    'PhabricatorSyntaxHighlighter' => 'applications/markup/syntax',
     'PhabricatorTaskmasterDaemon' => 'infrastructure/daemon/workers/taskmaster',
     'PhabricatorTestCase' => 'infrastructure/testing/testcase',
     'PhabricatorTimelineCursor' => 'infrastructure/daemon/timeline/storage/cursor',
diff --git a/src/applications/differential/parser/changeset/DifferentialChangesetParser.php b/src/applications/differential/parser/changeset/DifferentialChangesetParser.php
index edc6153d08..c43aaf9ec7 100644
--- a/src/applications/differential/parser/changeset/DifferentialChangesetParser.php
+++ b/src/applications/differential/parser/changeset/DifferentialChangesetParser.php
@@ -873,10 +873,7 @@ EOSYNTHETIC;
     $this->isTopLevel = (($range_start === null) && ($range_len === null));
 
 
-    $this->highlightEngine = new PhutilDefaultSyntaxHighlighterEngine();
-    $this->highlightEngine->setConfig(
-      'pygments.enabled',
-      PhabricatorEnv::getEnvConfig('pygments.enabled'));
+    $this->highlightEngine = PhabricatorSyntaxHighlighter::newEngine();
 
     $this->tryCacheStuff();
 
diff --git a/src/applications/differential/parser/changeset/__init__.php b/src/applications/differential/parser/changeset/__init__.php
index 34285ac975..7ca3982ed4 100644
--- a/src/applications/differential/parser/changeset/__init__.php
+++ b/src/applications/differential/parser/changeset/__init__.php
@@ -14,7 +14,7 @@ phutil_require_module('phabricator', 'applications/differential/storage/changese
 phutil_require_module('phabricator', 'applications/differential/storage/diff');
 phutil_require_module('phabricator', 'applications/differential/view/inlinecomment');
 phutil_require_module('phabricator', 'applications/files/uri');
-phutil_require_module('phabricator', 'infrastructure/env');
+phutil_require_module('phabricator', 'applications/markup/syntax');
 phutil_require_module('phabricator', 'infrastructure/javelin/markup');
 phutil_require_module('phabricator', 'storage/queryfx');
 
@@ -24,7 +24,6 @@ phutil_require_module('phutil', 'filesystem/tempfile');
 phutil_require_module('phutil', 'future');
 phutil_require_module('phutil', 'future/exec');
 phutil_require_module('phutil', 'markup');
-phutil_require_module('phutil', 'markup/syntax/engine/default');
 phutil_require_module('phutil', 'utils');
 
 
diff --git a/src/applications/diffusion/controller/file/DiffusionBrowseFileController.php b/src/applications/diffusion/controller/file/DiffusionBrowseFileController.php
index 3bf7e7ee3b..eac0ce27ff 100644
--- a/src/applications/diffusion/controller/file/DiffusionBrowseFileController.php
+++ b/src/applications/diffusion/controller/file/DiffusionBrowseFileController.php
@@ -179,16 +179,11 @@ class DiffusionBrowseFileController extends DiffusionController {
 
         list($text_list, $rev_list, $blame_dict) = $file_query->getBlameData();
 
-        $highlight_engine = new PhutilDefaultSyntaxHighlighterEngine();
-        $highlight_engine->setConfig(
-          'pygments.enabled',
-          PhabricatorEnv::getEnvConfig('pygments.enabled'));
-
-        $text_list = explode(
-          "\n",
-          $highlight_engine->highlightSource(
-            $highlight_engine->getLanguageFromFilename($path),
-            implode("\n", $text_list)));
+        $text_list = implode("\n", $text_list);
+        $text_list = PhabricatorSyntaxHighlighter::highlightWithFilename(
+          $path,
+          $text_list);
+        $text_list = explode("\n", $text_list);
 
         $rows = $this->buildDisplayRows($text_list, $rev_list, $blame_dict,
           $needs_blame, $drequest, $file_query, $selected);
diff --git a/src/applications/diffusion/controller/file/__init__.php b/src/applications/diffusion/controller/file/__init__.php
index 8b61c73968..7bba4cebcd 100644
--- a/src/applications/diffusion/controller/file/__init__.php
+++ b/src/applications/diffusion/controller/file/__init__.php
@@ -8,13 +8,12 @@
 
 phutil_require_module('phabricator', 'applications/diffusion/controller/base');
 phutil_require_module('phabricator', 'applications/diffusion/query/filecontent/base');
+phutil_require_module('phabricator', 'applications/markup/syntax');
 phutil_require_module('phabricator', 'infrastructure/celerity/api');
-phutil_require_module('phabricator', 'infrastructure/env');
 phutil_require_module('phabricator', 'infrastructure/javelin/api');
 phutil_require_module('phabricator', 'view/layout/panel');
 
 phutil_require_module('phutil', 'markup');
-phutil_require_module('phutil', 'markup/syntax/engine/default');
 phutil_require_module('phutil', 'utils');
 
 
diff --git a/src/applications/markup/syntax/PhabricatorSyntaxHighlighter.php b/src/applications/markup/syntax/PhabricatorSyntaxHighlighter.php
new file mode 100644
index 0000000000..52597ec333
--- /dev/null
+++ b/src/applications/markup/syntax/PhabricatorSyntaxHighlighter.php
@@ -0,0 +1,51 @@
+<?php
+
+/*
+ * Copyright 2011 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 markup
+ */
+final class PhabricatorSyntaxHighlighter {
+
+  public static function newEngine() {
+    $engine = new PhutilDefaultSyntaxHighlighterEngine();
+
+    $config = array(
+      'pygments.enabled' => PhabricatorEnv::getEnvConfig('pygments.enabled'),
+      'filename.map'     => PhabricatorEnv::getEnvConfig('syntax.filemap'),
+    );
+
+    foreach ($config as $key => $value) {
+      $engine->setConfig($key, $value);
+    }
+
+    return $engine;
+  }
+
+  public static function highlightWithFilename($filename, $source) {
+    $engine = self::newEngine();
+    $language = $engine->getLanguageFromFilename($filename);
+    return $engine->getHighlightFuture($language, $source)->resolve();
+  }
+
+  public static function highlightWithLanguage($language, $source) {
+    $engine = self::newEngine();
+    return $engine->getHighlightFuture($language, $source)->resolve();
+  }
+
+
+}
diff --git a/src/applications/markup/syntax/__init__.php b/src/applications/markup/syntax/__init__.php
new file mode 100644
index 0000000000..230b375ab6
--- /dev/null
+++ b/src/applications/markup/syntax/__init__.php
@@ -0,0 +1,14 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'infrastructure/env');
+
+phutil_require_module('phutil', 'markup/syntax/engine/default');
+
+
+phutil_require_source('PhabricatorSyntaxHighlighter.php');
diff --git a/src/applications/paste/controller/view/PhabricatorPasteViewController.php b/src/applications/paste/controller/view/PhabricatorPasteViewController.php
index 2809395853..90816f9de7 100644
--- a/src/applications/paste/controller/view/PhabricatorPasteViewController.php
+++ b/src/applications/paste/controller/view/PhabricatorPasteViewController.php
@@ -89,23 +89,19 @@ class PhabricatorPasteViewController extends PhabricatorPasteController {
     require_celerity_resource('diffusion-source-css');
     require_celerity_resource('syntax-highlighting-css');
 
-    $highlight_engine = new PhutilDefaultSyntaxHighlighterEngine();
-    $highlight_engine->setConfig(
-      'pygments.enabled',
-      PhabricatorEnv::getEnvConfig('pygments.enabled'));
-
-
     $language = $paste->getLanguage();
+    $source = $file->loadFileData();
     if (empty($language)) {
-      $language = $highlight_engine->getLanguageFromFilename(
-        $paste->getTitle());
+      $source = PhabricatorSyntaxHighlighter::highlightWithFilename(
+        $paste->getTitle(),
+        $source);
+    } else {
+      $source = PhabricatorSyntaxHighlighter::highlightWithLanguage(
+        $language,
+        $source);
     }
 
-    $text_list = explode(
-      "\n",
-      $highlight_engine->highlightSource(
-        $language,
-        $file->loadFileData()));
+    $text_list = explode("\n", $source);
 
     $rows = $this->buildDisplayRows($text_list);
 
diff --git a/src/applications/paste/controller/view/__init__.php b/src/applications/paste/controller/view/__init__.php
index fc6f4b8546..527fc99e51 100644
--- a/src/applications/paste/controller/view/__init__.php
+++ b/src/applications/paste/controller/view/__init__.php
@@ -10,14 +10,13 @@ phutil_require_module('phabricator', 'aphront/response/400');
 phutil_require_module('phabricator', 'aphront/response/404');
 phutil_require_module('phabricator', 'applications/files/storage/file');
 phutil_require_module('phabricator', 'applications/files/uri');
+phutil_require_module('phabricator', 'applications/markup/syntax');
 phutil_require_module('phabricator', 'applications/paste/controller/base');
 phutil_require_module('phabricator', 'applications/paste/storage/paste');
 phutil_require_module('phabricator', 'infrastructure/celerity/api');
-phutil_require_module('phabricator', 'infrastructure/env');
 phutil_require_module('phabricator', 'view/layout/panel');
 
 phutil_require_module('phutil', 'markup');
-phutil_require_module('phutil', 'markup/syntax/engine/default');
 phutil_require_module('phutil', 'utils');