Index: t3lib/class.t3lib_extmgm.php
===================================================================
--- t3lib/class.t3lib_extmgm.php	(Revision 5714)
+++ t3lib/class.t3lib_extmgm.php	(Arbeitskopie)
@@ -1202,8 +1202,20 @@
 	public static function typo3_loadExtensions() {
 		global $TYPO3_CONF_VARS;

+			// Select mode how to load extensions in order to speed up the FE
+		if (TYPO3_MODE == 'FE') {
+			if (!($extLoadInContext = $TYPO3_CONF_VARS['EXT']['extList_FE'])) {
+					// fall back to standard 'extList' if 'extList_FE' is not (yet) set
+				$extLoadInContext = $TYPO3_CONF_VARS['EXT']['extList'];
+			}
+			$cacheFileSuffix = '_FE';
+		} else {
+			$extLoadInContext = $TYPO3_CONF_VARS['EXT']['extList'];
+			// Works as before
+			$cacheFileSuffix = '';
+		}
 			// Full list of extensions includes both required and extList:
-		$rawExtList = $TYPO3_CONF_VARS['EXT']['requiredExt'].','.$TYPO3_CONF_VARS['EXT']['extList'];
+		$rawExtList = $TYPO3_CONF_VARS['EXT']['requiredExt'].','.$extLoadInContext;

 			// Empty array as a start.
 		$extensions = array();
@@ -1211,7 +1223,7 @@
 			//
 		if ($rawExtList) {
 				// The cached File prefix.
-			$cacheFilePrefix = 'temp_CACHED';
+			$cacheFilePrefix = 'temp_CACHED' . $cacheFileSuffix;
 				// Setting the name for the cache files:
 			if (intval($TYPO3_CONF_VARS['EXT']['extCache'])==1)	$cacheFilePrefix.= '_ps'.substr(t3lib_div::shortMD5(PATH_site.'|'.$GLOBALS['TYPO_VERSION']), 0, 4);
 			if (intval($TYPO3_CONF_VARS['EXT']['extCache'])==2)	$cacheFilePrefix.= '_'.t3lib_div::shortMD5($rawExtList);
@@ -1223,8 +1235,7 @@
 			} else {	// ... but if not, configure...

 					// Prepare reserved filenames:
-				$files = t3lib_div::trimExplode(',', 'ext_localconf.php,ext_tables.php,ext_tables.sql,ext_tables_static+adt.sql,ext_typoscript_constants.txt,ext_typoscript_editorcfg.txt,ext_typoscript_setup.txt', 1);
-
+				$files = array('ext_localconf.php','ext_tables.php','ext_tables.sql','ext_tables_static+adt.sql','ext_typoscript_constants.txt','ext_typoscript_editorcfg.txt','ext_typoscript_setup.txt');
 					// Traverse extensions and check their existence:
 				clearstatcache();	// Clear file state cache to make sure we get good results from is_dir()
 				$temp_extensions = array_unique(t3lib_div::trimExplode(',', $rawExtList, 1));
@@ -1348,15 +1359,20 @@
 	 * @internal
 	 */
 	public static function currentCacheFiles() {
-		global $TYPO3_LOADED_EXT;
-
-		if ($TYPO3_LOADED_EXT['_CACHEFILE']) {
-			if (t3lib_extMgm::isCacheFilesAvailable($TYPO3_LOADED_EXT['_CACHEFILE'])) {
-				return array(
-					PATH_typo3conf.$TYPO3_LOADED_EXT['_CACHEFILE'].'_ext_localconf.php',
-					PATH_typo3conf.$TYPO3_LOADED_EXT['_CACHEFILE'].'_ext_tables.php'
-				);
+		if (($cacheFilePrefix = $GLOBALS['TYPO3_LOADED_EXT']['_CACHEFILE'])) {
+			$cacheFilePrefixFE = str_replace('temp_CACHED','temp_CACHED_FE',$cacheFilePrefix);
+			$files = array();
+			if (t3lib_extMgm::isCacheFilesAvailable($cacheFilePrefix)) {
+				$files[] = PATH_typo3conf.$cacheFilePrefix.'_ext_localconf.php';
+				$files[] = PATH_typo3conf.$cacheFilePrefix.'_ext_tables.php';
 			}
+			if (t3lib_extMgm::isCacheFilesAvailable($cacheFilePrefixFE)) {
+				$files[] = PATH_typo3conf.$cacheFilePrefixFE.'_ext_localconf.php';
+				$files[] = PATH_typo3conf.$cacheFilePrefixFE.'_ext_tables.php';
+			}
+			if (!empty($files)) {
+				return $files;
+			}
 		}
 	}

Index: typo3/mod/tools/em/class.em_index.php
===================================================================
--- typo3/mod/tools/em/class.em_index.php	(Revision 5714)
+++ typo3/mod/tools/em/class.em_index.php	(Arbeitskopie)
@@ -3958,6 +3958,8 @@
 	function writeNewExtensionList($newExtList)	{
 		global $TYPO3_CONF_VARS;

+		$strippedExtensionList = $this->stripNonFrontendExtensions($newExtList);
+
 		// Instance of install tool
 		$instObj = new t3lib_install;
 		$instObj->allowUpdateLocalConf =1;
@@ -3966,13 +3968,34 @@
 		// Get lines from localconf file
 		$lines = $instObj->writeToLocalconf_control();
 		$instObj->setValueInLocalconfFile($lines, '$TYPO3_CONF_VARS[\'EXT\'][\'extList\']', $newExtList);
+		$instObj->setValueInLocalconfFile($lines, '$TYPO3_CONF_VARS[\'EXT\'][\'extList_FE\']', $strippedExtensionList);
 		$instObj->writeToLocalconf_control($lines);

 		$TYPO3_CONF_VARS['EXT']['extList'] = $newExtList;
+		$TYPO3_CONF_VARS['EXT']['extList_FE'] = $strippedExtensionList;
 		$this->removeCacheFiles();
 	}

 	/**
+	 * Removes unneeded extensions from the frontend based on
+	 * EMCONF doNotLoadInFE = 1
+	 *
+	 * @param string $extList
+	 * @return string
+	 */
+	function stripNonFrontendExtensions($extList) {
+		$fullExtList = $this->getInstalledExtensions();
+		$extListArray = t3lib_div::trimExplode(',', $extList);
+		foreach ($extListArray as $arrayKey => $extKey) {
+			if ($fullExtList[0][$extKey]['EM_CONF']['doNotLoadInFE'] == 1) {
+				unset($extListArray[$arrayKey]);
+			}
+		}
+		$nonFEList = implode(',', $extListArray);
+		return $nonFEList;
+	}
+
+	/**
 	 * Writes the TSstyleconf values to "localconf.php"
 	 * Removes the temp_CACHED* files before return.
 	 *