FreePBX is a full-featured PBX web application. If you’ve looked into Asterisk, you know that it doesn’t come with any “built in” programming. You can’t plug a phone into it and make it work without editing configuration files, writing dialplans, and various messing about. FreePBX simplifies this by giving you pre-programmed functionality accessible by a user-friendly web interfaces that allows you to have a fully functional PBX pretty much straight away with no programming required.
For More Information Visit : http://www.freepbx.org