Tinode [https://github.com/tinode/chat] Tinode is a free, unlimited, and flexible open source messaging platform that’s been built mobile-first. Instant, free, global communication should be a fundamental feature of today's internet. Our aim is to enable everyone to create a high-quality chat experience outside of the walled gardens that exist today. * * * Instant messaging server. Backend in pure Go (license GPL 3.0), client-side binding in Java, Javascript, and Swift, as well as gRPC client support for C++, C#, Go, Java, Node, PHP, Python, Ruby, Objective-C, etc. (license Apache 2.0). Wire transport is JSON over websocket (long polling is also available) for custom bindings, or protobuf with gRPC. Persistent storage is any one of RethinkDB, MySQL or MongoDB. A third-party unsupported DynamoDB adapter also exists. Other databases can be supported by writing custom adapters. Tinode is not XMPP/Jabber. It is not compatible with XMPP. It's meant as a replacement for XMPP. On the surface, it's a lot like open source WhatsApp or Telegram. Version 0.17. This is beta-quality software: feature-complete and stable but probably with a few bugs.