Requirements

This document has been moved to https://docs.google.com/document/d/1f-5ZoMgbtwdjP1W1VU1WXF2LajJx3pyL7usv7JdGnRM/edit?usp=sharing - ask e.g. mgottschlag for write access.

• Instant messaging
• Multi device
• Synchronized server based history (synchronization between all clients)
• Multi platform (Linux, OSX, Windows, iOS, Android,...)
• Accessible
• End-to-end encryption
• Transparent key management and synchronisation
• Backward compatible to xmpp servers (?)
• Transmit messages between xmpp and xmpp2 servers
  • I (Mathias) think this is a bad idea: It almost duplicates the server implementation work and introduces usability problems (why can't I send a file to this specific contact?) as well as potential security problems (chats with xmpp contacts cannot be easily encrypted). I'd also argue that backwards compatibility is not really necessary, as people will just be running two IM clients instead.
• File transfer (pictures, ...), with optional server side storage (pictures are a part of the synchronized chat history)
• Federation
• DynDNS compatibility
• Spontaneous multiuser chats unlimited user count
• Synchronize notifications between clients
• Optional (!) notification that the peer has read a message (?)
• Extension support
• Optional (?) audio/video chat support (likely as a protocol extension)

Clients

• Native mobile clients
  • ... with proper push notifications for improved battery life
• Independent client library
• Pidgin plugin
• Standalone desktop client (?)
• Web client (?)
• Smartphone: sync contact list with smartphone contact list (?)