Elastix!

FreePBX is a web-based open source GUI (graphical user interface) that controls and manages Asterisk (PBX), an open source communication server. FreePBX is licensed under the GNU General Public License (GPL), an open source license. FreePBX can be installed manually or as part of the pre-configured FreePBX Distro that includes the system OS, Asterisk, FreePBX GUI and assorted dependencies.

Wazo is mainly an IPBX that provides communication services such audio, video, and instant messaging based on the use of standard network technologies such as the TCP/IP protocol. It is interoperable with most market telephony systems and gives users access to flexible and advanced services without requiring specialized hardware.

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. FreeSWITCH also provides a stable telephony platform on which many telephony applications can be developed using a wide range of free tools.

Your Open Source Solution For Unified Comunnications And More…

XiVO is a scalable platform based on Asterisk that offers a free and complete PBX solution. It is licensed under the GPLv3.

Incredible PBX is a secure and feature-rich implementation of the Asterisk® PBX. By rethinking the PBX security model from the ground up.

Yate is a softswitch (concept of separating the network hardware from network software).

Ombutel is a joint venture of Telesoft and Xorcom that offers a free phone system based on the solid Linux and Asterisk platforms, offering whole new level of user experience with offers fully-responsive user interface that looks great, and is easy to use, on any screen size. Ombutel utilizes the latest technologies in Linux and Asterisk to provide a highly secure system on all levels.

PBX in a Flash is a 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. The Asterisk components are compiled from source during the install process which allows for easier adaptions later on. The system is update-able without re-install. A script collection on pbxinaflash.org allows for easy extension of the base system.

AsteriskNOW is the fastest way to get started building custom telephony solutions with Asterisk. Simply download the .iso file, burn it to a CD, drop it into the CD or DVD drive on the target computer and in less than 30 minutes you will have a full functional Asterisk system ready for your custom telephony application.

FreeSentral is a full IP PBX consisting of a Linux Distribution, an IP PBX and a Web Graphical User Interface for easy configuration