Extensions (such as the hieroglyphic module WikiHiero) are distributed separately. Drop them into this extensions directory and enable as per the extension's directions. If you are a developer, you want to fetch the extension tree in another directory and make a symbolic link: mediawiki/extensions$ ln -s ../../extensions-trunk/FooBarExt The extensions are available through Git: https://gerrit.wikimedia.org/r/#/admin/projects/ or Subversion: https://svn.wikimedia.org/svnroot/mediawiki/trunk/extensions/ You can find documentation and additional extensions on MediaWiki website: https://www.mediawiki.org/wiki/Category:Extensions Please note that under POSIX systems (Linux...), parent of a symbolic path refers to the link source, NOT to the target! You should check the env variable MW_INSTALL_PATH in case the extension is not in the default location. The following code snippet lets you override the default path: $IP = getenv( 'MW_INSTALL_PATH' ); if( $IP === false ) { $IP = __DIR__ . '/../..'; } require_once "$IP/maintenance/Maintenance.php"; // a MediaWiki core file