In order to make MediaWiki do something new, we first watched how it does some of the old things. In particular, how a new Wiki gets created. Here's a summary. When MediaWiki is first installed, there is no database. How does the engine know this, and what does it do to create one? Well, it doesn't actually check for a database. Instead, a clean installation of the MediaWiki scripts looks for a LocalSettings.php file in the top-level directory (which we'll call "~"). If that file isn't found, then the script ultimately serves up the content of ~/includes/templates/NoLocalSettings.php. The most significant thing on that page is a link to ~/config/index.php. Clicking on that link will take you to the installation script. The top of the page generated by that script will report on the environment, and the bottom half will contain a form to allow the wiki to be configured. In our case, the second bullet in the environment report says "Found database drivers for: MySQL" and the form Database config section has a single radio button for Database type, labelled "MySQL". It looks like this page will be a good place to start looking for what needs to change. Obviously we want to expand the found database drivers and to make an additional radio button available.