Intraweb Studio uses Firebird

“IntraWeb Studio is a professional Content Management System (CMS). It enables you to edit and manage your website in a very efficient and cost effective way.
All of your files and documents for a web site are kept in a repository. The repository may be located on your development machine or on an external repository server (IWS Pro and up). The repository is implemented in an SQL based DBMS. Currently IWS supports FireBird, IWS Personal and Desktop edition use an embedded version of FireBird – no special setup is required.”