Extension:SiteMatrix

The SiteMatrix extension adds a special page with a matrix of all sites of the Wikimedia Foundation. First a table of all normal language wikis, with blue links for existing wikis and red links for non-existing wikis. Below a list of other special projects (like Meta, Commons, Wikimania, ...), mostly the sites like.

Configuration
There are some variables that you need to change: You would also need to customise  to list the different wikis in your own wikifarm. Follow the template in SiteMatrix.php as a guide.
 * - The path to a list of language codes recognised by MediaWiki (example).
 * - The path to a list of wiki databases that are private (optional)
 * - The path to a list of wiki databases that are public, but only logged in users can edit. (optional)
 * - The path of a list of wiki databases that "closed" (optional)

Additional requirements
To ensure that the extension works correctly to your needs, there are a few dependencies to this extension:
 * - To tell the extension all the wiki databases that exist in your wikifarm.
 * - To feed the extension with the correct links to the different wikis in your wikifarm.

API
This extension adds an API module that provides the same information as Special:SiteMatrix: a set of language groups plus special wikis.