You can add your extension to your MediaWiki installation using the following steps:
1. Download and install ExtensionFunctions.php
ExtensionFunctions.php is a helper file. Some newer extensions require this file. This file allows extensions to be modularized away from the MediaWiki core code. You can download this file from https://www.mediawiki.org/wiki/Download_from_SVN, and once you download, copy the ExtensionFunctions.php file to $IP/extensions/ sub-directory of your MediaWiki installation.2. Download your extension
A list of extensions documented on MediaWiki.org is available at https://www.mediawiki.org/wiki/Manual:Extensions. Matrix and a list of extensions stored in Wikimedia are available at https://phabricator.wikimedia.org/diffusion/.3. Install your extension
You can install extensions by simply adding a line in the LocalSettings.php file in the following manner:include("extensions/NewExtensionName.php");
Note: Replace NewExtensionName.php with your new extension file name.
You may refer Readme file if it requires any special steps to take care of before the installation.
