The web interface is written in PHP, using base library PHPlib functionality like session support, authenting and templates. The underlying DBMS is accessed using instance of a subclass of Db_Sql from PHPlib.
The cron script that uses service providers website to update service instance status in database and sends users notifications about changes is written in Perl. This is because PHP does not support parallel execution - a neccessary feature to complete large number of http requests in reasonable time.