* [Elastix](http://www.elastix.org) - Unified communications server software based on Asterisk. ([Source Code](https://svn.code.sf.net/p/elastix/code/trunk/)) `GPLv2``PHP`
* [Freepbx](http://www.freepbx.org) - Web-based open source GUI that controls and manages Asterisk. ([Source Code](http://git.freepbx.org/projects/FREEPBX)) `GPLv2``PHP`
* [Kazoo](http://2600hz.org/) - KAZOO is an open-source, highly scalable software platform designed to provide carrier-grade VoIP switch functions and features. ([Source Code](https://github.com/2600hz/KAZOO)) `MPLv1.1``Erlang`
* [XiVO](http://www.xivo.io) - Unified communications server software based on Asterisk. ([Source Code](https://github.com/xivo-pbx)) `GPLv3``Python`