Elastix is a software-based PBX powered by 3CX and based on Debian. An open-standards solution, Elastix is an easy to install and manage UC system compatible with popular IP phones, gateways and SIP trunks.
Elastix is complete with unified communications features such as integrated WebRTC video conferencing, chat, presence and softphones and smartphone clients for Windows, Mac, iOS and Android.
VitalPBX is a free telephone and communications PBX system for companies. It is a complete platform that can be installed on the physical hardware on the site or as a hosted application. VitalPBX acts as the upper layer interface for the Linux base and then Asterisk (one of the most popular communication toolkits in the world). For this reason, VitalPBX is the graphic user interface between you and the complex world of modern communications. VitalPBX will help you implement a secure...
This Webmin module aids in configuring the Dahdi interface to Asterisk
...This Webmin module aids in configuring the legacy hardware devices to Asterisk PBX. Webmin was chosen because Webmin is a mature web based GUI platform that concentrates on the hardware side of a server. Webmin allows controlled secure root access to the hardware. Other web based GUIs concentrate on the software side of configuring Asterisk and do not provide root access directly.
For the latest information on installing the module in FreePBX go to the Wiki - How to Install page