- [RetroShare](http://retroshare.org) - Secured and decentralized communication system. Offers decentralized chat, forums, messaging, file transfer. ([Source Code](https://github.com/RetroShare/RetroShare)) `GPL-2.0``С++`
- [Rocket.Chat](https://rocket.chat/) - Teamchat solution similar to Gitter.im or Slack. ([Source Code](https://github.com/RocketChat/Rocket.Chat)) `MIT``Nodejs`
- [Shhh](https://github.com/smallwat3r/shhh) - Keep secrets out of emails or chat logs, share them using secure links with passphrase and expiration dates. `MIT``Python`
- [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)) `GPL-3.0``C++`
- [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/SpectrumIM/spectrum2)) `GPL-3.0``C++`
- [Spreed](https://www.spreed.me/) - WebRTC audio/video calls, conferencing server, and web client. ([Source Code](https://github.com/strukturag/spreed-webrtc)) `AGPL-3.0``Go`
- [Synapse](http://matrix.org/docs/projects/server/synapse.html) - Server for [Matrix](https://matrix.org/), an open standard for decentralized persistent communication. ([Source Code](https://github.com/matrix-org/synapse)) `Apache-2.0``Python`
- [Matrix Console Web](https://matrix.org/docs/projects/client/matrix-console-web) - 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-2.0``Javascript`
Nathan Rew
3 years ago