added RetroShare

README.md

@@ -187,6 +187,7 @@ For preconfigured mail server solutions, see [Self-hosting Solutions](#self-host
   * [Synapse](https://matrix.org/blog/project/synapse/) - 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](https://matrix.org/blog/project/matrix-console-web/) - 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`
   * [Tox](https://tox.chat/) -  A distributed, secure messenger with audio and video chat capabilities. `GPLv3` `C`
+  * [RetroShare](http://retroshare.org) - Secured and decentralized communication system. Offers decentralized chat, forums, messaging, file transfer. ([Source code](https://github.com/RetroShare/RetroShare)) `GPLv2``С++`
 
 ### Social Networks and Forums
 
@@ -325,6 +326,7 @@ Some [Groupware](#groupware) solutions also feature file sharing synchronization
   * [Syncthing](http://syncthing.net/) - Syncthing is an open source peer-to-peer file synchronisation tool ([Source code](https://github.com/syncthing/syncthing)) - `MPLv2` `Go`
   * [Tahoe-LAFS](https://www.tahoe-lafs.org/trac/tahoe-lafs) - Tahoe-LAFS is a Free and Open decentralized cloud storage system. It distributes your data across multiple servers. Even if some of the servers fail or are taken over by an attacker, the entire file store continues to function correctly, preserving your privacy and security.
   * [Z-Push](https://z-push.org/) - an implementation of Microsoft’s [ActiveSync](https://en.wikipedia.org/wiki/ActiveSync) protocol 
+  * [RetroShare](http://retroshare.org) - Secured and decentralized communication system. Offers decentralized chat, forums, messaging, file transfer. ([Source code](https://github.com/RetroShare/RetroShare)) `GPLv2` `C++`
 
 
 ## Games