diff --git a/src/applications/cache/spec/PhabricatorCacheSpec.php b/src/applications/cache/spec/PhabricatorCacheSpec.php
--- a/src/applications/cache/spec/PhabricatorCacheSpec.php
+++ b/src/applications/cache/spec/PhabricatorCacheSpec.php
@@ -78,32 +78,18 @@
     return $this->entryCount;
   }
 
-  protected function raiseInstallAPCIssue() {
-    $message = pht(
-      "Installing the PHP extension 'APC' (Alternative PHP Cache) will ".
-      "dramatically improve performance. Note that APC versions 3.1.14 and ".
-      "3.1.15 are broken; 3.1.13 is recommended instead.");
-
-    return $this
-      ->newIssue('extension.apc')
-      ->setShortName(pht('APC'))
-      ->setName(pht("PHP Extension 'APC' Not Installed"))
-      ->setMessage($message)
-      ->addPHPExtension('apc');
-  }
-
   protected function raiseEnableAPCIssue() {
-    $summary = pht('Enabling APC/APCu will improve performance.');
+    $summary = pht('Enabling APCu will improve performance.');
     $message = pht(
-      'The APC or APCu PHP extensions are installed, but not enabled in your '.
-      'PHP configuration. Enabling these extensions will improve performance. '.
-      'Edit the "%s" setting to enable these extensions.',
+      'The APCu PHP extension is installed, but not enabled in your '.
+      'PHP configuration. Enabling this extension will improve performance. '.
+      'Edit the "%s" setting to enable this extension.',
       'apc.enabled');
 
     return $this
       ->newIssue('extension.apc.enabled')
-      ->setShortName(pht('APC/APCu Disabled'))
-      ->setName(pht('APC/APCu Extensions Not Enabled'))
+      ->setShortName(pht('APCu Disabled'))
+      ->setName(pht('APCu Extension Not Enabled'))
       ->setSummary($summary)
       ->setMessage($message)
       ->addPHPConfig('apc.enabled');
diff --git a/src/applications/cache/spec/PhabricatorDataCacheSpec.php b/src/applications/cache/spec/PhabricatorDataCacheSpec.php
--- a/src/applications/cache/spec/PhabricatorDataCacheSpec.php
+++ b/src/applications/cache/spec/PhabricatorDataCacheSpec.php
@@ -16,10 +16,7 @@
   public static function getActiveCacheSpec() {
     $spec = new PhabricatorDataCacheSpec();
 
-    // NOTE: If APCu is installed, it reports that APC is installed.
-    if (extension_loaded('apc') && !extension_loaded('apcu')) {
-      $spec->initAPCSpec();
-    } else if (extension_loaded('apcu')) {
+    if (extension_loaded('apcu')) {
       $spec->initAPCuSpec();
     } else {
       $spec->initNoneSpec();
@@ -28,22 +25,6 @@
     return $spec;
   }
 
-  private function initAPCSpec() {
-    $this
-      ->setName(pht('APC User Cache'))
-      ->setVersion(phpversion('apc'));
-
-    if (ini_get('apc.enabled')) {
-      $this
-        ->setIsEnabled(true)
-        ->setClearCacheCallback('apc_clear_cache');
-      $this->initAPCCommonSpec();
-    } else {
-      $this->setIsEnabled(false);
-      $this->raiseEnableAPCIssue();
-    }
-  }
-
   private function initAPCuSpec() {
     $this
       ->setName(pht('APCu'))
@@ -67,21 +48,17 @@
   }
 
   private function initNoneSpec() {
-    if (version_compare(phpversion(), '5.5', '>=')) {
-      $message = pht(
-        'Installing the "APCu" PHP extension will improve performance. '.
-        'This extension is strongly recommended. Without it, this software '.
-        'must rely on a very inefficient disk-based cache.');
+    $message = pht(
+      'Installing the "APCu" PHP extension will improve performance. '.
+      'This extension is strongly recommended. Without it, this software '.
+      'must rely on a very inefficient disk-based cache.');
 
-      $this
-        ->newIssue('extension.apcu')
-        ->setShortName(pht('APCu'))
-        ->setName(pht('PHP Extension "APCu" Not Installed'))
-        ->setMessage($message)
-        ->addPHPExtension('apcu');
-    } else {
-      $this->raiseInstallAPCIssue();
-    }
+    $this
+      ->newIssue('extension.apcu')
+      ->setShortName(pht('APCu'))
+      ->setName(pht('PHP Extension "APCu" Not Installed'))
+      ->setMessage($message)
+      ->addPHPExtension('apcu');
   }
 
   private function initAPCCommonSpec() {
@@ -107,8 +84,8 @@
       $state = array();
       foreach ($cache as $item) {
         // Some older versions of APCu report the cachekey as "key", while
-        // newer APCu and APC report it as "info". Just check both indexes
-        // for commpatibility. See T13164 for details.
+        // newer APCu report it as "info". Just check both indexes for
+        // compatibility. See T13164 for details.
 
         $info = idx($item, 'info');
         if ($info === null) {
diff --git a/src/applications/cache/spec/PhabricatorOpcodeCacheSpec.php b/src/applications/cache/spec/PhabricatorOpcodeCacheSpec.php
--- a/src/applications/cache/spec/PhabricatorOpcodeCacheSpec.php
+++ b/src/applications/cache/spec/PhabricatorOpcodeCacheSpec.php
@@ -5,10 +5,7 @@
   public static function getActiveCacheSpec() {
     $spec = new PhabricatorOpcodeCacheSpec();
 
-    // NOTE: If APCu is installed, it reports that APC is installed.
-    if (extension_loaded('apc') && !extension_loaded('apcu')) {
-      $spec->initAPCSpec();
-    } else if (extension_loaded('Zend OPcache')) {
+    if (extension_loaded('Zend OPcache')) {
       $spec->initOpcacheSpec();
     } else {
       $spec->initNoneSpec();
@@ -17,94 +14,6 @@
     return $spec;
   }
 
-  private function initAPCSpec() {
-    $this
-      ->setName(pht('APC'))
-      ->setVersion(phpversion('apc'));
-
-    if (ini_get('apc.enabled')) {
-      $this
-        ->setIsEnabled(true)
-        ->setClearCacheCallback('apc_clear_cache');
-
-      $mem = apc_sma_info();
-      $this->setTotalMemory($mem['num_seg'] * $mem['seg_size']);
-
-      $info = apc_cache_info();
-      $this->setUsedMemory($info['mem_size']);
-
-      $write_lock = ini_get('apc.write_lock');
-      $slam_defense = ini_get('apc.slam_defense');
-
-      if (!$write_lock || $slam_defense) {
-        $summary = pht('Adjust APC settings to quiet unnecessary errors.');
-
-        $message = pht(
-          'Some versions of APC may emit unnecessary errors into the '.
-          'error log under the current APC settings. To resolve this, '.
-          'enable "%s" and disable "%s" in your PHP configuration.',
-          'apc.write_lock',
-          'apc.slam_defense');
-
-        $this
-          ->newIssue('extension.apc.write-lock')
-          ->setShortName(pht('Noisy APC'))
-          ->setName(pht('APC Has Noisy Configuration'))
-          ->setSummary($summary)
-          ->setMessage($message)
-          ->addPHPConfig('apc.write_lock')
-          ->addPHPConfig('apc.slam_defense');
-      }
-
-      $is_dev = PhabricatorEnv::getEnvConfig('phabricator.developer-mode');
-      $is_stat_enabled = ini_get('apc.stat');
-      if ($is_stat_enabled && !$is_dev) {
-        $summary = pht(
-          '"%s" is currently enabled, but should probably be disabled.',
-          'apc.stat');
-
-        $message = pht(
-          'The "%s" setting is currently enabled in your PHP configuration. '.
-          'In production mode, "%s" should be disabled. '.
-          'This will improve performance slightly.',
-          'apc.stat',
-          'apc.stat');
-
-        $this
-          ->newIssue('extension.apc.stat-enabled')
-          ->setShortName(pht('"%s" Enabled', 'apc.stat'))
-          ->setName(pht('"%s" Enabled in Production', 'apc.stat'))
-          ->setSummary($summary)
-          ->setMessage($message)
-          ->addPHPConfig('apc.stat')
-          ->addPhabricatorConfig('phabricator.developer-mode');
-      } else if (!$is_stat_enabled && $is_dev) {
-        $summary = pht(
-          '"%s" is currently disabled, but should probably be enabled.',
-          'apc.stat');
-
-        $message = pht(
-          'The "%s" setting is currently disabled in your PHP configuration, '.
-          'but this software is running in development mode. This option '.
-          'should normally be enabled in development so you do not need to '.
-          'restart anything after making changes to the code.',
-          'apc.stat');
-
-        $this
-          ->newIssue('extension.apc.stat-disabled')
-          ->setShortName(pht('"%s" Disabled', 'apc.stat'))
-          ->setName(pht('"%s" Disabled in Development', 'apc.stat'))
-          ->setSummary($summary)
-          ->setMessage($message)
-          ->addPHPConfig('apc.stat')
-          ->addPhabricatorConfig('phabricator.developer-mode');
-      }
-    } else {
-      $this->setIsEnabled(false);
-      $this->raiseEnableAPCIssue();
-    }
-  }
-
   private function initOpcacheSpec() {
     $this
       ->setName(pht('Zend OPcache'))
@@ -187,19 +96,15 @@
   }
 
   private function initNoneSpec() {
-    if (version_compare(phpversion(), '5.5', '>=')) {
-      $message = pht(
-        'Installing the "Zend OPcache" extension will dramatically improve '.
-        'performance.');
+    $message = pht(
+      'Installing the "Zend OPcache" extension will dramatically improve '.
+      'performance.');
 
-      $this
-        ->newIssue('extension.opcache')
-        ->setShortName(pht('OPcache'))
-        ->setName(pht('Zend OPcache Not Installed'))
-        ->setMessage($message)
-        ->addPHPExtension('Zend OPcache');
-    } else {
-      $this->raiseInstallAPCIssue();
-    }
+    $this
+      ->newIssue('extension.opcache')
+      ->setShortName(pht('OPcache'))
+      ->setName(pht('Zend OPcache Not Installed'))
+      ->setMessage($message)
+      ->addPHPExtension('Zend OPcache');
   }
 }
diff --git a/src/infrastructure/cache/PhutilKeyValueCache.php b/src/infrastructure/cache/PhutilKeyValueCache.php
--- a/src/infrastructure/cache/PhutilKeyValueCache.php
+++ b/src/infrastructure/cache/PhutilKeyValueCache.php
@@ -1,7 +1,7 @@
 <?php
 
 /**
- * Interface to a key-value cache like Memcache or APC. This class provides a
+ * Interface to a key-value cache like Memcache or APCu. This class provides a
  * uniform interface to multiple different key-value caches and integration
  * with PhutilServiceProfiler.
  *
@@ -14,8 +14,8 @@
 
 
   /**
-   * Determine if the cache is available. For example, the APC cache tests if
-   * APC is installed. If this method returns false, the cache is not
+   * Determine if the cache is available. For example, the APCu cache tests if
+   * APCu is installed. If this method returns false, the cache is not
    * operational and can not be used.
    *
    * @return bool True if the cache can be used.