index.php
This file is the entry point for all http requests. Even if the URL is simplified, .htaccess routes all requests to this file.
The file includes api.php to access all code and the configuration.
It then checks the global variables from the request: $name, $name2, $action, $query, $content, $comment
It creates the user based on login or session variables.
It creates the menus based on the user rights.
It routes to the special pages based on $action. If there is a modification of the database, it is handled in index.php first.
The output is routed to the skins script.
Finally, a log line is written.