PBX in a Flash is described as 'PBX system based on Asterisk, FreePBX and CentOS, coming as an ISO download. A two stage installation process allows for more flexibility for the installation of the PBX specific components' and is an app in the Social & Communications category. There are more than 10 alternatives to PBX in a Flash for a variety of platforms, including Linux, Mac, Windows, iPhone and BSD. The best alternative is Wazo, which is both free and Open Source. Other great apps like PBX in a Flash are FreeSWITCH (Free, Open Source), The Incredible PBX (Free, Open Source), XiVO (Free, Open Source) and VitalPBX (Free).
FreeSWITCH is a scalable open source cross-platform telephony platform designed to route and interconnect popular communication protocols using audio, video, text or any other form of media. It was created in 2006 to fill the void left by proprietary commercial solutions.
VitalPBX is a full-feature PBX (phone system) based on Linux and Asterisk. VitalPBX is extremely easy to use, fast and secure. VitalPBX is free to use, including for commercial use, with no limitations of the amount of users.
More than a PBX, with Elastix you can communicate with your customers through voice, video and live chat from anywhere. Built-in video conferencing, website live chat and smartphone apps, ensure your agents remain productive through one unified mobile solution.
The Taridium ipbx is a complete software-based VoIP PBX system that replaces traditional proprietary hardware PBX. ipbx runs on an open source operating system (Linux) without the need for extra software licenses and is based on the SIP standard.