FreeSWITCH
FreeSWITCH is a free and open-source application server for real-time communication, WebRTC, telecommunications, video and Voice over Internet Protocol (VoIP). Multiplatform, it runs on Linux, Windows, macOS and FreeBSD. It is used to build PBX systems, IVR services, videoconferencing with chat and screen sharing, wholesale least-cost routing, Session Border Controller (SBC) and embedded communication appliances. It has full support for encryption, ZRTP, DTLS, SIPS. It can act as a gateway between PSTN, SIP, WebRTC, and many other communication protocols. Its core library, libfreeswitch, can be embedded into other projects. It is licensed under the Mozilla Public License (MPL), a free software license.

History
The FreeSWITCH project was first announced in January 2006 at O'Reilly Media's ETEL Conference.  In June 2007, FreeSWITCH was selected by Truphone for use, and in August 2007, Gaboogie announced that it selected FreeSWITCH as its conferencing platform.

FreeSWITCH's first official 1.0.0 release (Phoenix) was on May 26, 2008. A minor 1.0.1 patch release came out on July 24, 2008. At ClueCon 2012 Anthony Minessale announced the release of FreeSWITCH version 1.2.0 and that the FreeSWITCH development team had adopted separate stable (version 1.2) and development (version 1.3) branches.

FreeSWITCH 1.4, released at early 2014, is the first version support SIP over Websocket and WebRTC.

FreeSWITCH 1.6 added support for video transcoding and video conferencing, Verto protocol for WebRTC, and all WebRTC codecs and standards.

FreeSWITCH 1.8 was released at ClueCon in 2018 with further updates and stability improvements to the project.

SignalWire Inc was founded in 2018 to provide commercial cloud telecommunication services utilizing an elastic FreeSWITCH core, and provide a permanent commercial sponsor for the open source project that was controlled by the founders of FreeSWITCH. It then acquired FreeSWITCH Solutions.

Design
According to the lead designer, Anthony Minessale, FreeSWITCH is intended to be a softswitch that is built on top of a solid core, driven by a state machine.  The stated goals of the project include stability, scalability, and abstraction.

Derived products
FreeSWITCH is a core component in many PBX in a box commercial products and open-source projects. Some of the commercial products are hardware and software bundles, for which the manufacturer supports and releases the software as open source.

 BigBlueButton is built on top of FreeSWITCH

See also

List of free and open-source software packages
List of SIP software – other SIP related programs

References

Free VoIP software
Lua (programming language)-scriptable software
Software using the Mozilla license