@ -241,6 +241,7 @@ Some [Groupware](#groupware) solutions also feature calendar/address book editin
* [Ring](https://ring.cx/) - Free software for universal communication which respects freedoms and privacy of its users. ([Source Code](https://github.com/savoirfairelinux/ring-project)) `GPLv3``C++`
* [Rocket.Chat](https://rocket.chat/) - Teamchat solution similar to Gitter.im or Slack. ([Source Code](https://github.com/RocketChat/Rocket.Chat)) `MIT``Nodejs`
* [Spectrum 2](http://spectrum.im/) - Spectrum 2 is an open source instant messaging transport. It allows users to chat together even when they are using different IM networks. ([Source Code](https://github.com/hanzz/spectrum2)) `GPLv3``C++`
* [Spreed](https://www.spreed.me/) - WebRTC audio/video calls, conferencing server, and web client. ([Source Code](https://github.com/strukturag/spreed-webrtc)) `AGPLv3``Go`
* [Synapse](http://matrix.org/docs/projects/server/synapse.html) - A server for [Matrix](https://matrix.org/), an open standard for decentralized persistent communication. ([Source Code](https://github.com/matrix-org/synapse)) `Apache``Python`
* [Matrix Console Web](http://matrix.org/docs/projects/client/matrix-console.html) - A web client meant to be a showcase of Matrix capabilities, and reference implementation of the Matrix standard. ([Source Code](https://github.com/matrix-org/matrix-angular-sdk)) `Apache``Javascript`
* [twister](http://twister.net.co/) - Fully decentralized P2P microblogging platform leveraging the free software implementations of Bitcoin and BitTorrent protocols. ([Source Code](https://github.com/miguelfreitas/twister-core)) `BSD/MIT``C++`
* [Vanilla Forums](https://vanillaforums.org/) - Simple and flexible forum software. ([Source Code](https://github.com/vanilla/vanilla)) `GPLv2``PHP`
### Instant Messaging
* [Spectrum 2](http://spectrum.im/) - Spectrum 2 is an open source instant messaging transport. It allows users to chat together even when they are using different IM networks.