Architecture:MediaWiki/installer layer

From mediawiki.org

The installer layer contains the special kind of code used during installation. On the one hand, this code may have knowledge of the entire system, and may access code in all layers. On the other hand, the installer runs without the application having been properly initialized. For this reason, it can only carefully interact with certain parts of the code, according to the progress of the installation process.

There are two entry points for installation: one for the command line (maintenance/install.php) and one for web based installation (located at mw-config/index.php).