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
@@ -2655,9 +2655,9 @@
     'PhabricatorEditorMultipleSetting' => 'applications/settings/setting/PhabricatorEditorMultipleSetting.php',
     'PhabricatorEditorSetting' => 'applications/settings/setting/PhabricatorEditorSetting.php',
     'PhabricatorElasticFulltextStorageEngine' => 'applications/search/fulltextstorage/PhabricatorElasticFulltextStorageEngine.php',
-    'PhabricatorElasticSearchHost' => 'infrastructure/cluster/search/PhabricatorElasticSearchHost.php',
-    'PhabricatorElasticSearchQueryBuilder' => 'applications/search/fulltextstorage/PhabricatorElasticSearchQueryBuilder.php',
-    'PhabricatorElasticSearchSetupCheck' => 'applications/config/check/PhabricatorElasticSearchSetupCheck.php',
+    'PhabricatorElasticsearchHost' => 'infrastructure/cluster/search/PhabricatorElasticsearchHost.php',
+    'PhabricatorElasticsearchQueryBuilder' => 'applications/search/fulltextstorage/PhabricatorElasticsearchQueryBuilder.php',
+    'PhabricatorElasticsearchSetupCheck' => 'applications/config/check/PhabricatorElasticsearchSetupCheck.php',
     'PhabricatorEmailAddressesSettingsPanel' => 'applications/settings/panel/PhabricatorEmailAddressesSettingsPanel.php',
     'PhabricatorEmailContentSource' => 'applications/metamta/contentsource/PhabricatorEmailContentSource.php',
     'PhabricatorEmailDeliverySettingsPanel' => 'applications/settings/panel/PhabricatorEmailDeliverySettingsPanel.php',
@@ -7750,8 +7750,8 @@
     'PhabricatorEditorMultipleSetting' => 'PhabricatorSelectSetting',
     'PhabricatorEditorSetting' => 'PhabricatorStringSetting',
     'PhabricatorElasticFulltextStorageEngine' => 'PhabricatorFulltextStorageEngine',
-    'PhabricatorElasticSearchHost' => 'PhabricatorSearchHost',
-    'PhabricatorElasticSearchSetupCheck' => 'PhabricatorSetupCheck',
+    'PhabricatorElasticsearchHost' => 'PhabricatorSearchHost',
+    'PhabricatorElasticsearchSetupCheck' => 'PhabricatorSetupCheck',
     'PhabricatorEmailAddressesSettingsPanel' => 'PhabricatorSettingsPanel',
     'PhabricatorEmailContentSource' => 'PhabricatorContentSource',
     'PhabricatorEmailDeliverySettingsPanel' => 'PhabricatorEditEngineSettingsPanel',
diff --git a/src/applications/config/check/PhabricatorElasticSearchSetupCheck.php b/src/applications/config/check/PhabricatorElasticsearchSetupCheck.php.lowercase
rename from src/applications/config/check/PhabricatorElasticSearchSetupCheck.php
rename to src/applications/config/check/PhabricatorElasticsearchSetupCheck.php.lowercase
--- a/src/applications/config/check/PhabricatorElasticSearchSetupCheck.php
+++ b/src/applications/config/check/PhabricatorElasticsearchSetupCheck.php.lowercase
@@ -1,6 +1,6 @@
 <?php
 
-final class PhabricatorElasticSearchSetupCheck extends PhabricatorSetupCheck {
+final class PhabricatorElasticsearchSetupCheck extends PhabricatorSetupCheck {
 
   public function getDefaultGroup() {
     return self::GROUP_OTHER;
@@ -16,7 +16,7 @@
         // ignore the error
         continue;
       }
-      if ($host instanceof PhabricatorElasticSearchHost) {
+      if ($host instanceof PhabricatorElasticsearchHost) {
         $index_exists = null;
         $index_sane = null;
         try {
diff --git a/src/applications/config/check/PhabricatorMySQLSetupCheck.php b/src/applications/config/check/PhabricatorMySQLSetupCheck.php
--- a/src/applications/config/check/PhabricatorMySQLSetupCheck.php
+++ b/src/applications/config/check/PhabricatorMySQLSetupCheck.php
@@ -145,7 +145,7 @@
           "be able to find search results for common words. You can gain ".
           "access to this option by upgrading MySQL to a more recent ".
           "version.\n\n".
-          "You can ignore this warning if you plan to configure ElasticSearch ".
+          "You can ignore this warning if you plan to configure Elasticsearch ".
           "later, or aren't concerned about searching for common words.",
           $host_name,
           phutil_tag('tt', array(), 'ft_stopword_file'));
@@ -180,7 +180,7 @@
           "To make search more useful, you can use an alternate stopword ".
           "file with fewer words. Alternatively, if you aren't concerned ".
           "about searching for common words, you can ignore this warning. ".
-          "If you later plan to configure ElasticSearch, you can also ignore ".
+          "If you later plan to configure Elasticsearch, you can also ignore ".
           "this warning: this stopword file only affects MySQL fulltext ".
           "indexes.\n\n".
           "To choose a different stopword file, add this to your %s file ".
@@ -231,7 +231,7 @@
           "You can change this setting to 3 to allow these words to be ".
           "indexed. Alternatively, you can ignore this warning if you are ".
           "not concerned about searching for 3-letter words. If you later ".
-          "plan to configure ElasticSearch, you can also ignore this warning: ".
+          "plan to configure Elasticsearch, you can also ignore this warning: ".
           "only MySQL fulltext search is affected.\n\n".
           "To reduce the minimum word length to 3, add this to your %s file ".
           "(in the %s section) and then restart %s:\n\n".
diff --git a/src/applications/maniphest/query/ManiphestTaskQuery.php b/src/applications/maniphest/query/ManiphestTaskQuery.php
--- a/src/applications/maniphest/query/ManiphestTaskQuery.php
+++ b/src/applications/maniphest/query/ManiphestTaskQuery.php
@@ -514,7 +514,7 @@
       ->setParameter('query', $this->fullTextSearch);
 
     // NOTE: Setting this to something larger than 10,000 will raise errors in
-    // ElasticSearch, and billions of results won't fit in memory anyway.
+    // Elasticsearch, and billions of results won't fit in memory anyway.
     $fulltext_query->setParameter('limit', 10000);
     $fulltext_query->setParameter('types',
       array(ManiphestTaskPHIDType::TYPECONST));
diff --git a/src/applications/search/fulltextstorage/PhabricatorElasticFulltextStorageEngine.php b/src/applications/search/fulltextstorage/PhabricatorElasticFulltextStorageEngine.php
--- a/src/applications/search/fulltextstorage/PhabricatorElasticFulltextStorageEngine.php
+++ b/src/applications/search/fulltextstorage/PhabricatorElasticFulltextStorageEngine.php
@@ -32,19 +32,13 @@
   }
 
   public function getHostType() {
-    return new PhabricatorElasticSearchHost($this);
+    return new PhabricatorElasticsearchHost($this);
   }
 
-  /**
-   * @return PhabricatorElasticSearchHost
-   */
   public function getHostForRead() {
     return $this->getService()->getAnyHostForRole('read');
   }
 
-  /**
-   * @return PhabricatorElasticSearchHost
-   */
   public function getHostForWrite() {
     return $this->getService()->getAnyHostForRole('write');
   }
@@ -148,7 +142,7 @@
   }
 
   private function buildSpec(PhabricatorSavedQuery $query) {
-    $q = new PhabricatorElasticSearchQueryBuilder('bool');
+    $q = new PhabricatorElasticsearchQueryBuilder('bool');
     $query_string = $query->getParameter('query');
     if (strlen($query_string)) {
       $fields = $this->getTypeConstants('PhabricatorSearchDocumentFieldType');
@@ -305,7 +299,7 @@
       $exceptions);
   }
 
-  public function indexExists(PhabricatorElasticSearchHost $host = null) {
+  public function indexExists(PhabricatorElasticsearchHost $host = null) {
     if (!$host) {
       $host = $this->getHostForRead();
     }
@@ -439,7 +433,7 @@
     return $data;
   }
 
-  public function indexIsSane(PhabricatorElasticSearchHost $host = null) {
+  public function indexIsSane(PhabricatorElasticsearchHost $host = null) {
     if (!$host) {
       $host = $this->getHostForRead();
     }
@@ -518,7 +512,7 @@
     $this->executeRequest($host, '/', $data, 'PUT');
   }
 
-  public function getIndexStats(PhabricatorElasticSearchHost $host = null) {
+  public function getIndexStats(PhabricatorElasticsearchHost $host = null) {
     if ($this->version < 2) {
       return false;
     }
@@ -542,7 +536,7 @@
     );
   }
 
-  private function executeRequest(PhabricatorElasticSearchHost $host, $path,
+  private function executeRequest(PhabricatorElasticsearchHost $host, $path,
     array $data, $method = 'GET') {
 
     $uri = $host->getURI($path);
@@ -576,7 +570,7 @@
     } catch (PhutilJSONParserException $ex) {
       $host->didHealthCheck(false);
       throw new PhutilProxyException(
-        pht('ElasticSearch server returned invalid JSON!'),
+        pht('Elasticsearch server returned invalid JSON!'),
         $ex);
     }
 
diff --git a/src/applications/search/fulltextstorage/PhabricatorElasticSearchQueryBuilder.php b/src/applications/search/fulltextstorage/PhabricatorElasticsearchQueryBuilder.php.lowercase
rename from src/applications/search/fulltextstorage/PhabricatorElasticSearchQueryBuilder.php
rename to src/applications/search/fulltextstorage/PhabricatorElasticsearchQueryBuilder.php.lowercase
--- a/src/applications/search/fulltextstorage/PhabricatorElasticSearchQueryBuilder.php
+++ b/src/applications/search/fulltextstorage/PhabricatorElasticsearchQueryBuilder.php.lowercase
@@ -1,6 +1,6 @@
 <?php
 
-class PhabricatorElasticSearchQueryBuilder {
+class PhabricatorElasticsearchQueryBuilder {
   protected $name;
   protected $clauses = array();
 
diff --git a/src/infrastructure/cluster/search/PhabricatorElasticSearchHost.php b/src/infrastructure/cluster/search/PhabricatorElasticsearchHost.php.lowercase
rename from src/infrastructure/cluster/search/PhabricatorElasticSearchHost.php
rename to src/infrastructure/cluster/search/PhabricatorElasticsearchHost.php.lowercase
--- a/src/infrastructure/cluster/search/PhabricatorElasticSearchHost.php
+++ b/src/infrastructure/cluster/search/PhabricatorElasticsearchHost.php.lowercase
@@ -1,6 +1,6 @@
 <?php
 
-final class PhabricatorElasticSearchHost
+final class PhabricatorElasticsearchHost
   extends PhabricatorSearchHost {
 
   private $version = 5;
@@ -21,7 +21,7 @@
   }
 
   public function getDisplayName() {
-    return pht('ElasticSearch');
+    return pht('Elasticsearch');
   }
 
   public function getStatusViewColumns() {