diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -716,6 +716,7 @@
     'DiffusionController' => 'applications/diffusion/controller/DiffusionController.php',
     'DiffusionCreateRepositoriesCapability' => 'applications/diffusion/capability/DiffusionCreateRepositoriesCapability.php',
     'DiffusionDaemonLockException' => 'applications/diffusion/exception/DiffusionDaemonLockException.php',
+    'DiffusionDatasourceEngineExtension' => 'applications/diffusion/engineextension/DiffusionDatasourceEngineExtension.php',
     'DiffusionDefaultEditCapability' => 'applications/diffusion/capability/DiffusionDefaultEditCapability.php',
     'DiffusionDefaultPushCapability' => 'applications/diffusion/capability/DiffusionDefaultPushCapability.php',
     'DiffusionDefaultViewCapability' => 'applications/diffusion/capability/DiffusionDefaultViewCapability.php',
@@ -844,7 +845,6 @@
     'DiffusionQueryCommitsConduitAPIMethod' => 'applications/diffusion/conduit/DiffusionQueryCommitsConduitAPIMethod.php',
     'DiffusionQueryConduitAPIMethod' => 'applications/diffusion/conduit/DiffusionQueryConduitAPIMethod.php',
     'DiffusionQueryPathsConduitAPIMethod' => 'applications/diffusion/conduit/DiffusionQueryPathsConduitAPIMethod.php',
-    'DiffusionQuickSearchEngineExtension' => 'applications/diffusion/engineextension/DiffusionQuickSearchEngineExtension.php',
     'DiffusionRawDiffQuery' => 'applications/diffusion/query/rawdiff/DiffusionRawDiffQuery.php',
     'DiffusionRawDiffQueryConduitAPIMethod' => 'applications/diffusion/conduit/DiffusionRawDiffQueryConduitAPIMethod.php',
     'DiffusionReadmeView' => 'applications/diffusion/view/DiffusionReadmeView.php',
@@ -2745,8 +2745,11 @@
     'PhabricatorDatabaseRef' => 'infrastructure/cluster/PhabricatorDatabaseRef.php',
     'PhabricatorDatabaseRefParser' => 'infrastructure/cluster/PhabricatorDatabaseRefParser.php',
     'PhabricatorDatabaseSetupCheck' => 'applications/config/check/PhabricatorDatabaseSetupCheck.php',
+    'PhabricatorDatasourceApplicationEngineExtension' => 'applications/meta/engineextension/PhabricatorDatasourceApplicationEngineExtension.php',
     'PhabricatorDatasourceEditField' => 'applications/transactions/editfield/PhabricatorDatasourceEditField.php',
     'PhabricatorDatasourceEditType' => 'applications/transactions/edittype/PhabricatorDatasourceEditType.php',
+    'PhabricatorDatasourceEngine' => 'applications/search/engine/PhabricatorDatasourceEngine.php',
+    'PhabricatorDatasourceEngineExtension' => 'applications/search/engineextension/PhabricatorDatasourceEngineExtension.php',
     'PhabricatorDateFormatSetting' => 'applications/settings/setting/PhabricatorDateFormatSetting.php',
     'PhabricatorDateTimeSettingsPanel' => 'applications/settings/panel/PhabricatorDateTimeSettingsPanel.php',
     'PhabricatorDebugController' => 'applications/system/controller/PhabricatorDebugController.php',
@@ -3316,7 +3319,7 @@
     'PhabricatorMetronomicTriggerClock' => 'infrastructure/daemon/workers/clock/PhabricatorMetronomicTriggerClock.php',
     'PhabricatorModularTransaction' => 'applications/transactions/storage/PhabricatorModularTransaction.php',
     'PhabricatorModularTransactionType' => 'applications/transactions/storage/PhabricatorModularTransactionType.php',
-    'PhabricatorMonogramQuickSearchEngineExtension' => 'applications/typeahead/engineextension/PhabricatorMonogramQuickSearchEngineExtension.php',
+    'PhabricatorMonogramDatasourceEngineExtension' => 'applications/typeahead/engineextension/PhabricatorMonogramDatasourceEngineExtension.php',
     'PhabricatorMonospacedFontSetting' => 'applications/settings/setting/PhabricatorMonospacedFontSetting.php',
     'PhabricatorMonospacedTextareasSetting' => 'applications/settings/setting/PhabricatorMonospacedTextareasSetting.php',
     'PhabricatorMotivatorProfileMenuItem' => 'applications/search/menuitem/PhabricatorMotivatorProfileMenuItem.php',
@@ -3615,6 +3618,7 @@
     'PhabricatorPeopleCreateController' => 'applications/people/controller/PhabricatorPeopleCreateController.php',
     'PhabricatorPeopleCreateGuidanceContext' => 'applications/people/guidance/PhabricatorPeopleCreateGuidanceContext.php',
     'PhabricatorPeopleDatasource' => 'applications/people/typeahead/PhabricatorPeopleDatasource.php',
+    'PhabricatorPeopleDatasourceEngineExtension' => 'applications/people/engineextension/PhabricatorPeopleDatasourceEngineExtension.php',
     'PhabricatorPeopleDeleteController' => 'applications/people/controller/PhabricatorPeopleDeleteController.php',
     'PhabricatorPeopleDetailsProfileMenuItem' => 'applications/people/menuitem/PhabricatorPeopleDetailsProfileMenuItem.php',
     'PhabricatorPeopleDisableController' => 'applications/people/controller/PhabricatorPeopleDisableController.php',
@@ -3647,7 +3651,6 @@
     'PhabricatorPeopleProfileTasksController' => 'applications/people/controller/PhabricatorPeopleProfileTasksController.php',
     'PhabricatorPeopleProfileViewController' => 'applications/people/controller/PhabricatorPeopleProfileViewController.php',
     'PhabricatorPeopleQuery' => 'applications/people/query/PhabricatorPeopleQuery.php',
-    'PhabricatorPeopleQuickSearchEngineExtension' => 'applications/people/engineextension/PhabricatorPeopleQuickSearchEngineExtension.php',
     'PhabricatorPeopleRenameController' => 'applications/people/controller/PhabricatorPeopleRenameController.php',
     'PhabricatorPeopleRevisionsProfileMenuItem' => 'applications/people/menuitem/PhabricatorPeopleRevisionsProfileMenuItem.php',
     'PhabricatorPeopleSearchEngine' => 'applications/people/query/PhabricatorPeopleSearchEngine.php',
@@ -3910,8 +3913,6 @@
     'PhabricatorQueryOrderItem' => 'infrastructure/query/order/PhabricatorQueryOrderItem.php',
     'PhabricatorQueryOrderTestCase' => 'infrastructure/query/order/__tests__/PhabricatorQueryOrderTestCase.php',
     'PhabricatorQueryOrderVector' => 'infrastructure/query/order/PhabricatorQueryOrderVector.php',
-    'PhabricatorQuickSearchApplicationEngineExtension' => 'applications/meta/engineextension/PhabricatorQuickSearchApplicationEngineExtension.php',
-    'PhabricatorQuickSearchEngine' => 'applications/search/engine/PhabricatorQuickSearchEngine.php',
     'PhabricatorQuickSearchEngineExtension' => 'applications/search/engineextension/PhabricatorQuickSearchEngineExtension.php',
     'PhabricatorRateLimitRequestExceptionHandler' => 'aphront/handler/PhabricatorRateLimitRequestExceptionHandler.php',
     'PhabricatorRecaptchaConfigOptions' => 'applications/config/option/PhabricatorRecaptchaConfigOptions.php',
@@ -4950,12 +4951,12 @@
     'ProjectConduitAPIMethod' => 'applications/project/conduit/ProjectConduitAPIMethod.php',
     'ProjectCreateConduitAPIMethod' => 'applications/project/conduit/ProjectCreateConduitAPIMethod.php',
     'ProjectCreateProjectsCapability' => 'applications/project/capability/ProjectCreateProjectsCapability.php',
+    'ProjectDatasourceEngineExtension' => 'applications/project/engineextension/ProjectDatasourceEngineExtension.php',
     'ProjectDefaultEditCapability' => 'applications/project/capability/ProjectDefaultEditCapability.php',
     'ProjectDefaultJoinCapability' => 'applications/project/capability/ProjectDefaultJoinCapability.php',
     'ProjectDefaultViewCapability' => 'applications/project/capability/ProjectDefaultViewCapability.php',
     'ProjectEditConduitAPIMethod' => 'applications/project/conduit/ProjectEditConduitAPIMethod.php',
     'ProjectQueryConduitAPIMethod' => 'applications/project/conduit/ProjectQueryConduitAPIMethod.php',
-    'ProjectQuickSearchEngineExtension' => 'applications/project/engineextension/ProjectQuickSearchEngineExtension.php',
     'ProjectRemarkupRule' => 'applications/project/remarkup/ProjectRemarkupRule.php',
     'ProjectRemarkupRuleTestCase' => 'applications/project/remarkup/__tests__/ProjectRemarkupRuleTestCase.php',
     'ProjectReplyHandler' => 'applications/project/mail/ProjectReplyHandler.php',
@@ -5901,6 +5902,7 @@
     'DiffusionController' => 'PhabricatorController',
     'DiffusionCreateRepositoriesCapability' => 'PhabricatorPolicyCapability',
     'DiffusionDaemonLockException' => 'Exception',
+    'DiffusionDatasourceEngineExtension' => 'PhabricatorDatasourceEngineExtension',
     'DiffusionDefaultEditCapability' => 'PhabricatorPolicyCapability',
     'DiffusionDefaultPushCapability' => 'PhabricatorPolicyCapability',
     'DiffusionDefaultViewCapability' => 'PhabricatorPolicyCapability',
@@ -6032,7 +6034,6 @@
     'DiffusionQueryCommitsConduitAPIMethod' => 'DiffusionConduitAPIMethod',
     'DiffusionQueryConduitAPIMethod' => 'DiffusionConduitAPIMethod',
     'DiffusionQueryPathsConduitAPIMethod' => 'DiffusionQueryConduitAPIMethod',
-    'DiffusionQuickSearchEngineExtension' => 'PhabricatorQuickSearchEngineExtension',
     'DiffusionRawDiffQuery' => 'DiffusionFileFutureQuery',
     'DiffusionRawDiffQueryConduitAPIMethod' => 'DiffusionQueryConduitAPIMethod',
     'DiffusionReadmeView' => 'DiffusionView',
@@ -8254,8 +8255,11 @@
     'PhabricatorDatabaseRef' => 'Phobject',
     'PhabricatorDatabaseRefParser' => 'Phobject',
     'PhabricatorDatabaseSetupCheck' => 'PhabricatorSetupCheck',
+    'PhabricatorDatasourceApplicationEngineExtension' => 'PhabricatorDatasourceEngineExtension',
     'PhabricatorDatasourceEditField' => 'PhabricatorTokenizerEditField',
     'PhabricatorDatasourceEditType' => 'PhabricatorPHIDListEditType',
+    'PhabricatorDatasourceEngine' => 'Phobject',
+    'PhabricatorDatasourceEngineExtension' => 'Phobject',
     'PhabricatorDateFormatSetting' => 'PhabricatorSelectSetting',
     'PhabricatorDateTimeSettingsPanel' => 'PhabricatorEditEngineSettingsPanel',
     'PhabricatorDebugController' => 'PhabricatorController',
@@ -8880,7 +8884,7 @@
     'PhabricatorMetronomicTriggerClock' => 'PhabricatorTriggerClock',
     'PhabricatorModularTransaction' => 'PhabricatorApplicationTransaction',
     'PhabricatorModularTransactionType' => 'Phobject',
-    'PhabricatorMonogramQuickSearchEngineExtension' => 'PhabricatorQuickSearchEngineExtension',
+    'PhabricatorMonogramDatasourceEngineExtension' => 'PhabricatorDatasourceEngineExtension',
     'PhabricatorMonospacedFontSetting' => 'PhabricatorStringSetting',
     'PhabricatorMonospacedTextareasSetting' => 'PhabricatorSelectSetting',
     'PhabricatorMotivatorProfileMenuItem' => 'PhabricatorProfileMenuItem',
@@ -9248,6 +9252,7 @@
     'PhabricatorPeopleCreateController' => 'PhabricatorPeopleController',
     'PhabricatorPeopleCreateGuidanceContext' => 'PhabricatorGuidanceContext',
     'PhabricatorPeopleDatasource' => 'PhabricatorTypeaheadDatasource',
+    'PhabricatorPeopleDatasourceEngineExtension' => 'PhabricatorDatasourceEngineExtension',
     'PhabricatorPeopleDeleteController' => 'PhabricatorPeopleController',
     'PhabricatorPeopleDetailsProfileMenuItem' => 'PhabricatorProfileMenuItem',
     'PhabricatorPeopleDisableController' => 'PhabricatorPeopleController',
@@ -9280,7 +9285,6 @@
     'PhabricatorPeopleProfileTasksController' => 'PhabricatorPeopleProfileController',
     'PhabricatorPeopleProfileViewController' => 'PhabricatorPeopleProfileController',
     'PhabricatorPeopleQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
-    'PhabricatorPeopleQuickSearchEngineExtension' => 'PhabricatorQuickSearchEngineExtension',
     'PhabricatorPeopleRenameController' => 'PhabricatorPeopleController',
     'PhabricatorPeopleRevisionsProfileMenuItem' => 'PhabricatorProfileMenuItem',
     'PhabricatorPeopleSearchEngine' => 'PhabricatorApplicationSearchEngine',
@@ -9598,9 +9602,7 @@
       'Phobject',
       'Iterator',
     ),
-    'PhabricatorQuickSearchApplicationEngineExtension' => 'PhabricatorQuickSearchEngineExtension',
-    'PhabricatorQuickSearchEngine' => 'Phobject',
-    'PhabricatorQuickSearchEngineExtension' => 'Phobject',
+    'PhabricatorQuickSearchEngineExtension' => 'PhabricatorDatasourceEngineExtension',
     'PhabricatorRateLimitRequestExceptionHandler' => 'PhabricatorRequestExceptionHandler',
     'PhabricatorRecaptchaConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'PhabricatorRedirectController' => 'PhabricatorController',
@@ -10893,12 +10895,12 @@
     'ProjectConduitAPIMethod' => 'ConduitAPIMethod',
     'ProjectCreateConduitAPIMethod' => 'ProjectConduitAPIMethod',
     'ProjectCreateProjectsCapability' => 'PhabricatorPolicyCapability',
+    'ProjectDatasourceEngineExtension' => 'PhabricatorDatasourceEngineExtension',
     'ProjectDefaultEditCapability' => 'PhabricatorPolicyCapability',
     'ProjectDefaultJoinCapability' => 'PhabricatorPolicyCapability',
     'ProjectDefaultViewCapability' => 'PhabricatorPolicyCapability',
     'ProjectEditConduitAPIMethod' => 'PhabricatorEditEngineAPIMethod',
     'ProjectQueryConduitAPIMethod' => 'ProjectConduitAPIMethod',
-    'ProjectQuickSearchEngineExtension' => 'PhabricatorQuickSearchEngineExtension',
     'ProjectRemarkupRule' => 'PhabricatorObjectRemarkupRule',
     'ProjectRemarkupRuleTestCase' => 'PhabricatorTestCase',
     'ProjectReplyHandler' => 'PhabricatorApplicationTransactionReplyHandler',
diff --git a/src/applications/diffusion/engineextension/DiffusionQuickSearchEngineExtension.php b/src/applications/diffusion/engineextension/DiffusionDatasourceEngineExtension.php
rename from src/applications/diffusion/engineextension/DiffusionQuickSearchEngineExtension.php
rename to src/applications/diffusion/engineextension/DiffusionDatasourceEngineExtension.php
--- a/src/applications/diffusion/engineextension/DiffusionQuickSearchEngineExtension.php
+++ b/src/applications/diffusion/engineextension/DiffusionDatasourceEngineExtension.php
@@ -1,7 +1,7 @@
 <?php
 
-final class DiffusionQuickSearchEngineExtension
-  extends PhabricatorQuickSearchEngineExtension {
+final class DiffusionDatasourceEngineExtension
+  extends PhabricatorDatasourceEngineExtension {
 
   public function newQuickSearchDatasources() {
     return array(
diff --git a/src/applications/meta/engineextension/PhabricatorQuickSearchApplicationEngineExtension.php b/src/applications/meta/engineextension/PhabricatorDatasourceApplicationEngineExtension.php
rename from src/applications/meta/engineextension/PhabricatorQuickSearchApplicationEngineExtension.php
rename to src/applications/meta/engineextension/PhabricatorDatasourceApplicationEngineExtension.php
--- a/src/applications/meta/engineextension/PhabricatorQuickSearchApplicationEngineExtension.php
+++ b/src/applications/meta/engineextension/PhabricatorDatasourceApplicationEngineExtension.php
@@ -1,7 +1,7 @@
 <?php
 
-final class PhabricatorQuickSearchApplicationEngineExtension
-  extends PhabricatorQuickSearchEngineExtension {
+final class PhabricatorDatasourceApplicationEngineExtension
+  extends PhabricatorDatasourceEngineExtension {
 
   public function newQuickSearchDatasources() {
     return array(
diff --git a/src/applications/people/engineextension/PhabricatorPeopleQuickSearchEngineExtension.php b/src/applications/people/engineextension/PhabricatorPeopleDatasourceEngineExtension.php
rename from src/applications/people/engineextension/PhabricatorPeopleQuickSearchEngineExtension.php
rename to src/applications/people/engineextension/PhabricatorPeopleDatasourceEngineExtension.php
--- a/src/applications/people/engineextension/PhabricatorPeopleQuickSearchEngineExtension.php
+++ b/src/applications/people/engineextension/PhabricatorPeopleDatasourceEngineExtension.php
@@ -1,7 +1,7 @@
 <?php
 
-final class PhabricatorPeopleQuickSearchEngineExtension
-  extends PhabricatorQuickSearchEngineExtension {
+final class PhabricatorPeopleDatasourceEngineExtension
+  extends PhabricatorDatasourceEngineExtension {
 
   public function newQuickSearchDatasources() {
     return array(
diff --git a/src/applications/project/engineextension/ProjectQuickSearchEngineExtension.php b/src/applications/project/engineextension/ProjectDatasourceEngineExtension.php
rename from src/applications/project/engineextension/ProjectQuickSearchEngineExtension.php
rename to src/applications/project/engineextension/ProjectDatasourceEngineExtension.php
--- a/src/applications/project/engineextension/ProjectQuickSearchEngineExtension.php
+++ b/src/applications/project/engineextension/ProjectDatasourceEngineExtension.php
@@ -1,7 +1,7 @@
 <?php
 
-final class ProjectQuickSearchEngineExtension
-  extends PhabricatorQuickSearchEngineExtension {
+final class ProjectDatasourceEngineExtension
+  extends PhabricatorDatasourceEngineExtension {
 
   public function newQuickSearchDatasources() {
     return array(
diff --git a/src/applications/search/engine/PhabricatorDatasourceEngine.php b/src/applications/search/engine/PhabricatorDatasourceEngine.php
new file mode 100644
--- /dev/null
+++ b/src/applications/search/engine/PhabricatorDatasourceEngine.php
@@ -0,0 +1,8 @@
+<?php
+
+final class PhabricatorDatasourceEngine extends Phobject {
+
+  public function getAllQuickSearchDatasources() {
+    return PhabricatorDatasourceEngineExtension::getAllQuickSearchDatasources();
+  }
+}
diff --git a/src/applications/search/engine/PhabricatorQuickSearchEngine.php b/src/applications/search/engine/PhabricatorQuickSearchEngine.php
deleted file mode 100644
--- a/src/applications/search/engine/PhabricatorQuickSearchEngine.php
+++ /dev/null
@@ -1,8 +0,0 @@
-<?php
-
-final class PhabricatorQuickSearchEngine extends Phobject {
-
-  public function getAllDatasources() {
-    return PhabricatorQuickSearchEngineExtension::getAllDatasources();
-  }
-}
diff --git a/src/applications/search/engineextension/PhabricatorQuickSearchEngineExtension.php b/src/applications/search/engineextension/PhabricatorDatasourceEngineExtension.php
copy from src/applications/search/engineextension/PhabricatorQuickSearchEngineExtension.php
copy to src/applications/search/engineextension/PhabricatorDatasourceEngineExtension.php
--- a/src/applications/search/engineextension/PhabricatorQuickSearchEngineExtension.php
+++ b/src/applications/search/engineextension/PhabricatorDatasourceEngineExtension.php
@@ -1,10 +1,10 @@
 <?php
 
-abstract class PhabricatorQuickSearchEngineExtension extends Phobject {
+abstract class PhabricatorDatasourceEngineExtension extends Phobject {
 
   abstract public function newQuickSearchDatasources();
 
-  final public static function getAllDatasources() {
+  final public static function getAllQuickSearchDatasources() {
     $extensions = id(new PhutilClassMapQuery())
       ->setAncestorClass(__CLASS__)
       ->execute();
@@ -13,6 +13,7 @@
     foreach ($extensions as $extension) {
       $datasources[] = $extension->newQuickSearchDatasources();
     }
+
     return array_mergev($datasources);
   }
 }
diff --git a/src/applications/search/engineextension/PhabricatorQuickSearchEngineExtension.php b/src/applications/search/engineextension/PhabricatorQuickSearchEngineExtension.php
--- a/src/applications/search/engineextension/PhabricatorQuickSearchEngineExtension.php
+++ b/src/applications/search/engineextension/PhabricatorQuickSearchEngineExtension.php
@@ -1,18 +1,6 @@
 <?php
 
-abstract class PhabricatorQuickSearchEngineExtension extends Phobject {
-
-  abstract public function newQuickSearchDatasources();
-
-  final public static function getAllDatasources() {
-    $extensions = id(new PhutilClassMapQuery())
-      ->setAncestorClass(__CLASS__)
-      ->execute();
-
-    $datasources = array();
-    foreach ($extensions as $extension) {
-      $datasources[] = $extension->newQuickSearchDatasources();
-    }
-    return array_mergev($datasources);
-  }
-}
+// TODO: This is an older name "PhabricatorDatasourceEngineExtension" purely
+// to preserve compatibility that should be removed soon.
+abstract class PhabricatorQuickSearchEngineExtension
+  extends PhabricatorDatasourceEngineExtension {}
diff --git a/src/applications/search/typeahead/PhabricatorSearchDatasource.php b/src/applications/search/typeahead/PhabricatorSearchDatasource.php
--- a/src/applications/search/typeahead/PhabricatorSearchDatasource.php
+++ b/src/applications/search/typeahead/PhabricatorSearchDatasource.php
@@ -16,8 +16,8 @@
   }
 
   public function getComponentDatasources() {
-    $sources = id(new PhabricatorQuickSearchEngine())
-      ->getAllDatasources();
+    $sources = id(new PhabricatorDatasourceEngine())
+      ->getAllQuickSearchDatasources();
 
     // These results are always rendered in the full browse display mode, so
     // set the browse flag on all component sources.
diff --git a/src/applications/typeahead/engineextension/PhabricatorMonogramQuickSearchEngineExtension.php b/src/applications/typeahead/engineextension/PhabricatorMonogramDatasourceEngineExtension.php
rename from src/applications/typeahead/engineextension/PhabricatorMonogramQuickSearchEngineExtension.php
rename to src/applications/typeahead/engineextension/PhabricatorMonogramDatasourceEngineExtension.php
--- a/src/applications/typeahead/engineextension/PhabricatorMonogramQuickSearchEngineExtension.php
+++ b/src/applications/typeahead/engineextension/PhabricatorMonogramDatasourceEngineExtension.php
@@ -1,7 +1,7 @@
 <?php
 
-final class PhabricatorMonogramQuickSearchEngineExtension
-  extends PhabricatorQuickSearchEngineExtension {
+final class PhabricatorMonogramDatasourceEngineExtension
+  extends PhabricatorDatasourceEngineExtension {
 
   public function newQuickSearchDatasources() {
     return array(