diff --git a/apps/files_encryption/lib/cryptstream.php b/apps/files_encryption/lib/cryptstream.php
index e0020537563..46471911d94 100644
--- a/apps/files_encryption/lib/cryptstream.php
+++ b/apps/files_encryption/lib/cryptstream.php
@@ -31,9 +31,7 @@ class OC_CryptStream{
 	public static $sourceStreams=array();
 	private $source;
 	private $path;
-	private $readBuffer;//for streams that dont support seeking
 	private $meta=array();//header/meta for source stream
-	private $count;
 	private $writeCache;
 	private $size;
 	private static $rootView;
@@ -100,7 +98,6 @@ class OC_CryptStream{
 	
 	public function stream_write($data){
 		$length=strlen($data);
-		$written=0;
 		$currentPos=ftell($this->source);
 		if($this->writeCache){
 			$data=$this->writeCache.$data;
diff --git a/apps/files_external/lib/smb.php b/apps/files_external/lib/smb.php
index 5e34deb2337..8a5e993b1d0 100644
--- a/apps/files_external/lib/smb.php
+++ b/apps/files_external/lib/smb.php
@@ -15,8 +15,6 @@ class OC_FileStorage_SMB extends OC_FileStorage_StreamWrapper{
 	private $root;
 	private $share;
 
-	private static $tempFiles=array();
-
 	public function __construct($params){
 		$this->host=$params['host'];
 		$this->user=$params['user'];
diff --git a/apps/files_external/tests/ftp.php b/apps/files_external/tests/ftp.php
index 68481b4e66b..97796bca128 100644
--- a/apps/files_external/tests/ftp.php
+++ b/apps/files_external/tests/ftp.php
@@ -13,7 +13,6 @@ if(!is_array($config) or !isset($config['ftp']) or !$config['ftp']['run']){
 }else{
 	class Test_Filestorage_FTP extends Test_FileStorage {
 		private $config;
-		private $id;
 
 		public function setUp(){
 			$id=uniqid();
diff --git a/apps/files_external/tests/google.php b/apps/files_external/tests/google.php
index 08116f0e748..806db5a6aaa 100644
--- a/apps/files_external/tests/google.php
+++ b/apps/files_external/tests/google.php
@@ -28,7 +28,6 @@ if(!is_array($config) or !isset($config['google']) or !$config['google']['run'])
 	class Test_Filestorage_Google extends Test_FileStorage {
 		
 		private $config;
-		private $id;
 
 		public function setUp(){
 			$id=uniqid();
diff --git a/apps/files_external/tests/smb.php b/apps/files_external/tests/smb.php
index e1495b7480d..001ef842276 100644
--- a/apps/files_external/tests/smb.php
+++ b/apps/files_external/tests/smb.php
@@ -14,7 +14,6 @@ if(!is_array($config) or !isset($config['smb']) or !$config['smb']['run']){
 }else{
 	class Test_Filestorage_SMB extends Test_FileStorage {
 		private $config;
-		private $id;
 
 		public function setUp(){
 			$id=uniqid();
diff --git a/apps/files_external/tests/swift.php b/apps/files_external/tests/swift.php
index f0bde6ed605..1520c9473d3 100644
--- a/apps/files_external/tests/swift.php
+++ b/apps/files_external/tests/swift.php
@@ -13,7 +13,6 @@ if(!is_array($config) or !isset($config['swift']) or !$config['swift']['run']){
 }else{
 	class Test_Filestorage_SWIFT extends Test_FileStorage {
 		private $config;
-		private $id;
 
 		public function setUp(){
 			$id=uniqid();
diff --git a/apps/files_external/tests/webdav.php b/apps/files_external/tests/webdav.php
index 144659819b6..14abbef2cbf 100644
--- a/apps/files_external/tests/webdav.php
+++ b/apps/files_external/tests/webdav.php
@@ -13,7 +13,6 @@ if(!is_array($config) or !isset($config['webdav']) or !$config['webdav']['run'])
 }else{
 	class Test_Filestorage_DAV extends Test_FileStorage {
 		private $config;
-		private $id;
 
 		public function setUp(){
 			$id=uniqid();
diff --git a/apps/gallery/lib/album.php b/apps/gallery/lib/album.php
index 39d6d3aded1..701949d4d80 100644
--- a/apps/gallery/lib/album.php
+++ b/apps/gallery/lib/album.php
@@ -58,7 +58,7 @@ class OC_Gallery_Album {
 		return $stmt->execute($args);
 	}
 
-	public static function removeByName($owner, $name) { self::remove($ownmer, $name); }
+	public static function removeByName($owner, $name) { self::remove($owner, $name); }
 	public static function removeByPath($owner, $path) { self::remove($owner, null, $path); }
 	public static function removeByParentPath($owner, $parent) { self::remove($owner, null, null, $parent); }
 	
diff --git a/apps/gallery/lib/managers.php b/apps/gallery/lib/managers.php
index b6ade3d1b1e..575d962dbe3 100644
--- a/apps/gallery/lib/managers.php
+++ b/apps/gallery/lib/managers.php
@@ -29,7 +29,6 @@ class DatabaseManager {
 		$stmt = \OCP\DB::prepare('INSERT INTO *PREFIX*pictures_images_cache (uid_owner, path, width, height) VALUES (?, ?, ?, ?)');
 		$stmt->execute(array(\OCP\USER::getUser(), $path, $width, $height));
 		$ret = array('path' => $path, 'width' => $width, 'height' => $height);
-		unset($image);
 		$dir = dirname($path);
 		$this->cache[$dir][$path] = $ret;
 		return $ret;
diff --git a/apps/gallery/lib/tiles.php b/apps/gallery/lib/tiles.php
index 754734e609e..e36d26d3191 100644
--- a/apps/gallery/lib/tiles.php
+++ b/apps/gallery/lib/tiles.php
@@ -33,7 +33,7 @@ class TilesLine {
 	}
 
 	public function setAvailableSpace($space) {
-		$available_space = $space;
+		$this->available_space = $space;
 	}
 
 	public function getTilesCount() {
diff --git a/apps/media/lib_ampache.php b/apps/media/lib_ampache.php
index d35cca150b2..d5a093338cc 100644
--- a/apps/media/lib_ampache.php
+++ b/apps/media/lib_ampache.php
@@ -271,7 +271,6 @@ class OC_MEDIA_AMPACHE{
 </root>");
 			return;
 		}
-		global $SITEROOT;
 		$filter=$params['filter'];
 		$albums=OC_MEDIA_COLLECTION::getAlbums($filter);
 		$artist=OC_MEDIA_COLLECTION::getArtistName($filter);
diff --git a/apps/media/lib_collection.php b/apps/media/lib_collection.php
index e65930f551d..cacab8e959f 100644
--- a/apps/media/lib_collection.php
+++ b/apps/media/lib_collection.php
@@ -27,7 +27,6 @@ class OC_MEDIA_COLLECTION{
 	public static $uid;
 	private static $artistIdCache=array();
 	private static $albumIdCache=array();
-	private static $songIdCache=array();
 	private static $queries=array();
 	
 	/**
@@ -152,7 +151,7 @@ class OC_MEDIA_COLLECTION{
 			return $artistId;
 		}else{
 			$query=OCP\DB::prepare("INSERT INTO `*PREFIX*media_artists` (`artist_name`) VALUES (?)");
-			$result=$query->execute(array($name));
+			$query->execute(array($name));
 			return self::getArtistId($name);;
 		}
 	}
diff --git a/apps/media/lib_media.php b/apps/media/lib_media.php
index 9e687a4af2c..54502f42575 100644
--- a/apps/media/lib_media.php
+++ b/apps/media/lib_media.php
@@ -27,12 +27,12 @@ class OC_MEDIA{
 	 * @param array $params, parameters passed from OC_Hook
 	 */
 	public static function loginListener($params){
-		if(isset($_POST['user']) and $_POST['password']){
-			$name=$_POST['user'];
+		if(isset($params['uid']) and $params['password']){
+			$name=$params['uid'];
 			$query=OCP\DB::prepare("SELECT user_id from *PREFIX*media_users WHERE user_id LIKE ?");
 			$uid=$query->execute(array($name))->fetchAll();
 			if(count($uid)==0){
-				$password=hash('sha256',$_POST['password']);
+				$password=hash('sha256',$params['password']);
 				$query=OCP\DB::prepare("INSERT INTO *PREFIX*media_users (user_id, user_password_sha256) VALUES (?, ?);");
 				$query->execute(array($name,$password));
 			}
diff --git a/apps/remoteStorage/lib_remoteStorage.php b/apps/remoteStorage/lib_remoteStorage.php
index 42cd9c90f64..c1765640c5d 100644
--- a/apps/remoteStorage/lib_remoteStorage.php
+++ b/apps/remoteStorage/lib_remoteStorage.php
@@ -17,12 +17,11 @@ class OC_remoteStorage {
 		$user=OCP\USER::getUser();
 		$query=OCP\DB::prepare("SELECT token FROM *PREFIX*authtoken WHERE user=? AND appUrl=? AND category=? LIMIT 1");
 		$result=$query->execute(array($user, $appUrl, $categories));
-		$ret = array();
 		if($row=$result->fetchRow()) {
-		  return base64_encode('remoteStorage:'.$row['token']);
-    } else {
-      return false;
-    }
+			return base64_encode('remoteStorage:'.$row['token']);
+		} else {
+			return false;
+		}
 	}
 
 	public static function getAllTokens() {
@@ -42,13 +41,13 @@ class OC_remoteStorage {
 	public static function deleteToken($token) {
 		$user=OCP\USER::getUser();
 		$query=OCP\DB::prepare("DELETE FROM *PREFIX*authtoken WHERE token=? AND user=?");
-		$result=$query->execute(array($token,$user));
+		$query->execute(array($token,$user));
 		return 'unknown';//how can we see if any rows were affected?
 	}
 	private static function addToken($token, $appUrl, $categories){
 		$user=OCP\USER::getUser();
 		$query=OCP\DB::prepare("INSERT INTO *PREFIX*authtoken (`token`,`appUrl`,`user`,`category`) VALUES(?,?,?,?)");
-		$result=$query->execute(array($token,$appUrl,$user,$categories));
+		$query->execute(array($token,$appUrl,$user,$categories));
 	}
 	public static function createCategories($appUrl, $categories) {
 		$token=uniqid();
diff --git a/lib/archive/zip.php b/lib/archive/zip.php
index ff405ce098b..b2d6674d639 100644
--- a/lib/archive/zip.php
+++ b/lib/archive/zip.php
@@ -11,7 +11,6 @@ class OC_Archive_ZIP extends OC_Archive{
 	 * @var ZipArchive zip
 	 */
 	private $zip=null;
-	private $success=false;
 	private $path;
 	
 	function __construct($source){
diff --git a/lib/filecache/update.php b/lib/filecache/update.php
index dd77f491ca0..93b632acb4e 100644
--- a/lib/filecache/update.php
+++ b/lib/filecache/update.php
@@ -207,7 +207,6 @@ class OC_FileCache_Update{
 
 		$cached=OC_FileCache_Cached::get($oldPath,$root);
 		$oldSize=$cached['size'];
-		$size=$view->filesize($newPath);
 		OC_FileCache::increaseSize(dirname($oldPath),-$oldSize,$root);
 		OC_FileCache::increaseSize(dirname($newPath),$oldSize,$root);
 		OC_FileCache::move($oldPath,$newPath);
diff --git a/lib/filestorage/common.php b/lib/filestorage/common.php
index ba78fca80e5..fd389d3e2d7 100644
--- a/lib/filestorage/common.php
+++ b/lib/filestorage/common.php
@@ -220,7 +220,7 @@ abstract class OC_Filestorage_Common extends OC_Filestorage {
 		}
 		$tmpFile=OC_Helper::tmpFile($extension);
 		$target=fopen($tmpFile,'w');
-		$count=OC_Helper::streamCopy($source,$target);
+		OC_Helper::streamCopy($source,$target);
 		return $tmpFile;
 	}
 // 	abstract public function touch($path, $mtime=null);
diff --git a/lib/group/database.php b/lib/group/database.php
index fb173665eb8..2770ec185c4 100644
--- a/lib/group/database.php
+++ b/lib/group/database.php
@@ -41,7 +41,6 @@
  * Class for group management in a SQL Database (e.g. MySQL, SQLite)
  */
 class OC_Group_Database extends OC_Group_Backend {
-	private $userGroupCache=array();
 
 	/**
 	 * @brief Try to create a new group
@@ -116,7 +115,7 @@ class OC_Group_Database extends OC_Group_Backend {
 		// No duplicate entries!
 		if( !$this->inGroup( $uid, $gid )){
 			$query = OC_DB::prepare( "INSERT INTO `*PREFIX*group_user` ( `uid`, `gid` ) VALUES( ?, ? )" );
-			$result = $query->execute( array( $uid, $gid ));
+			$query->execute( array( $uid, $gid ));
 			return true;
 		}else{
 			return false;
@@ -133,7 +132,7 @@ class OC_Group_Database extends OC_Group_Backend {
 	 */
 	public function removeFromGroup( $uid, $gid ){
 		$query = OC_DB::prepare( "DELETE FROM *PREFIX*group_user WHERE uid = ? AND gid = ?" );
-		$result = $query->execute( array( $uid, $gid ));
+		$query->execute( array( $uid, $gid ));
 
 		return true;
 	}
diff --git a/lib/group/dummy.php b/lib/group/dummy.php
index 0825b10708a..1243891023f 100644
--- a/lib/group/dummy.php
+++ b/lib/group/dummy.php
@@ -126,7 +126,8 @@ class OC_Group_Dummy extends OC_Group_Backend {
 	 */
 	public function getUserGroups($uid){
 		$groups=array();
-		foreach($this->groups as $group=>$user){
+		$allGroups=array_keys($this->groups);
+		foreach($allGroups as $group){
 			if($this->inGroup($uid,$group)){
 				$groups[]=$group;
 			}
diff --git a/lib/group/example.php b/lib/group/example.php
index c18562db7a4..f9c62fb9789 100644
--- a/lib/group/example.php
+++ b/lib/group/example.php
@@ -34,7 +34,7 @@ abstract class OC_Group_Example {
 	 * Trys to create a new group. If the group name already exists, false will
 	 * be returned.
 	 */
-	public static function createGroup($gid){}
+	abstract public static function createGroup($gid);
 
 	/**
 	 * @brief delete a group
@@ -43,7 +43,7 @@ abstract class OC_Group_Example {
 	 *
 	 * Deletes a group and removes it from the group_user-table
 	 */
-	public static function deleteGroup($gid){}
+	abstract public static function deleteGroup($gid);
 
 	/**
 	 * @brief is user in group?
@@ -53,7 +53,7 @@ abstract class OC_Group_Example {
 	 *
 	 * Checks whether the user is member of a group or not.
 	 */
-	public static function inGroup($uid, $gid){}
+	abstract public static function inGroup($uid, $gid);
 
 	/**
 	 * @brief Add a user to a group
@@ -63,7 +63,7 @@ abstract class OC_Group_Example {
 	 *
 	 * Adds a user to a group.
 	 */
-	public static function addToGroup($uid, $gid){}
+	abstract public static function addToGroup($uid, $gid);
 
 	/**
 	 * @brief Removes a user from a group
@@ -73,7 +73,7 @@ abstract class OC_Group_Example {
 	 *
 	 * removes the user from a group.
 	 */
-	public static function removeFromGroup($uid,$gid){}
+	abstract public static function removeFromGroup($uid,$gid);
 
 	/**
 	 * @brief Get all groups a user belongs to
@@ -83,7 +83,7 @@ abstract class OC_Group_Example {
 	 * This function fetches all groups a user belongs to. It does not check
 	 * if the user exists at all.
 	 */
-	public static function getUserGroups($uid){}
+	abstract public static function getUserGroups($uid);
 
 	/**
 	 * @brief get a list of all groups
@@ -91,19 +91,19 @@ abstract class OC_Group_Example {
 	 *
 	 * Returns a list with all groups
 	 */
-	public static function getGroups(){}
+	abstract public static function getGroups();
 
 	/**
 	 * check if a group exists
 	 * @param string $gid
 	 * @return bool
 	 */
-	public function groupExists($gid){}
+	public function groupExists($gid);
 
 	/**
 	 * @brief get a list of all users in a group
 	 * @returns array with user ids
 	 */
-	public static function usersInGroup($gid){}
+	abstract public static function usersInGroup($gid);
 
 }
diff --git a/lib/public/app.php b/lib/public/app.php
index 38c51af9cdb..28411933beb 100644
--- a/lib/public/app.php
+++ b/lib/public/app.php
@@ -34,28 +34,6 @@ namespace OCP;
  * This class provides functions to manage apps in ownCloud
  */
 class App {
-
-        /**
-         * @brief Makes owncloud aware of this app
-         * @brief This call is deprecated and not necessary to use.
-         * @param $data array with all information
-         * @returns true/false
-         *
-         * This function registers the application. $data is an associative array.
-         * The following keys are required:
-         *   - id: id of the application, has to be unique ('addressbook')
-         *   - name: Human readable name ('Addressbook')
-         *   - version: array with Version (major, minor, bugfix) ( array(1, 0, 2))
-         *
-         * The following keys are optional:
-         *   - order: integer, that influences the position of your application in
-         *     a list of applications. Lower values come first.
-         *
-         */
-        public static function register( $data ){
-        }
-
-
         /**
          * @brief adds an entry to the navigation
          * @param $data array containing the data
diff --git a/lib/search/provider.php b/lib/search/provider.php
index 838ab696d04..b3ee79b4770 100644
--- a/lib/search/provider.php
+++ b/lib/search/provider.php
@@ -2,13 +2,17 @@
 /**
  * provides search functionalty
  */
-class OC_Search_Provider {
-	public function __construct($options){}
+abstract class OC_Search_Provider {
+	private $options;
+	
+	public function __construct($options){
+		$this->options=$options;
+	}
 	
 	/**
 	 * search for $query
 	 * @param string $query
 	 * @return array An array of OC_Search_Result's
 	 */
-	public function search($query){}
+	abstract public function search($query);
 }
diff --git a/lib/user/database.php b/lib/user/database.php
index a48b8357d64..cc27b3ddbfd 100644
--- a/lib/user/database.php
+++ b/lib/user/database.php
@@ -39,7 +39,6 @@ require_once 'phpass/PasswordHash.php';
  * Class for user management in a SQL Database (e.g. MySQL, SQLite)
  */
 class OC_User_Database extends OC_User_Backend {
-	static private $userGroupCache=array();
 	/**
 	 * @var PasswordHash
 	 */
@@ -87,7 +86,7 @@ class OC_User_Database extends OC_User_Backend {
 	public function deleteUser( $uid ){
 		// Delete user-group-relation
 		$query = OC_DB::prepare( "DELETE FROM `*PREFIX*users` WHERE uid = ?" );
-		$result = $query->execute( array( $uid ));
+		$query->execute( array( $uid ));
 		return true;
 	}
 
@@ -104,11 +103,10 @@ class OC_User_Database extends OC_User_Backend {
 			$hasher=$this->getHasher();
 			$hash = $hasher->HashPassword($password.OC_Config::getValue('passwordsalt', ''));
 			$query = OC_DB::prepare( "UPDATE *PREFIX*users SET password = ? WHERE uid = ?" );
-			$result = $query->execute( array( $hash, $uid ));
+			$query->execute( array( $hash, $uid ));
 
 			return true;
-		}
-		else{
+		}else{
 			return false;
 		}
 	}
diff --git a/lib/user/example.php b/lib/user/example.php
index 7f3fd1b8578..77246d8136c 100644
--- a/lib/user/example.php
+++ b/lib/user/example.php
@@ -35,9 +35,7 @@ abstract class OC_User_Example extends OC_User_Backend {
 		* Creates a new user. Basic checking of username is done in OC_User
 		* itself, not in its subclasses.
 		*/
-	public function createUser($uid, $password){
-		return OC_USER_BACKEND_NOT_IMPLEMENTED;
-	}
+	abstract public function createUser($uid, $password);
 
 	/**
 		* @brief Set password
@@ -47,9 +45,7 @@ abstract class OC_User_Example extends OC_User_Backend {
 		*
 		* Change the password of a user
 		*/
-	public function setPassword($uid, $password){
-		return OC_USER_BACKEND_NOT_IMPLEMENTED;
-	}
+	abstract public function setPassword($uid, $password);
 
 	/**
 		* @brief Check if the password is correct
@@ -60,7 +56,5 @@ abstract class OC_User_Example extends OC_User_Backend {
 		* Check if the password is correct without logging in the user
 		* returns the user id or false
 		*/
-	public function checkPassword($uid, $password){
-		return OC_USER_BACKEND_NOT_IMPLEMENTED;
-	}
+	abstract public function checkPassword($uid, $password);
 }
diff --git a/tests/lib/user/database.php b/tests/lib/user/database.php
index b2fcce93c5b..f484ffa78f7 100644
--- a/tests/lib/user/database.php
+++ b/tests/lib/user/database.php
@@ -21,7 +21,6 @@
 */
 
 class Test_User_Database extends Test_User_Backend {
-	private $user=array();
 	/**
 	 * get a new unique user name
 	 * test cases can override this in order to clean up created user