Add Chatwoot to Custom communication systems

README.md

@@ -248,6 +248,7 @@ _See https://en.wikipedia.org/wiki/Comparison_of_CalDAV_and_CardDAV_implementati
 ### Custom communication systems
 
 - [Centrifugo](https://github.com/centrifugal/centrifugo) - Language-agnostic real-time messaging (Websocket or SockJS) server. ([Demo](https://github.com/centrifugal/centrifugo#demo)) `MIT` `Go`
+- [Chatwoot](https://www.chatwoot.com) - Self-hosted customer communication platform, an alternative to Intercom & Zendesk. ([Source Code](https://github.com/chatwoot/chatwoot)) `MIT` `Ruby`
 - [Cherry](https://github.com/rafael-santiago/cherry) - Tiny webchat server. `GPL-2.0` `Go`
 - [Conduit](https://conduit.rs/) - A simple, fast, and reliable chat server powered by Matrix. ([Source Code](https://gitlab.com/famedly/conduit)) `Apache-2.0` `Rust`
 - [Darkwire.io](https://darkwire.io/) - End-to-end encrypted instant web chat. ([Source Code](https://github.com/darkwire/darkwire.io)) `MIT` `Nodejs`