JCollaborationFramework can be used, together with a Open Source XMPP Library, to establish a Collaboration Application for Chat, Collaborative WhiteBoard etc.
a xmpp lib based on OSGi Framework Equinox, support multi asynchronous xmppconnection. 一个基于OSGi框架Equinox开发的XMPP协议客户端库，并且可以异步的开启多个XMPP连接
A game server in Java that uses XMPP bots to ensure communication between players and referees.
Desktop whatsapp client
sandeshvahak is a desktop whatsapp client which uses whatsapp service to connect with other whatsapp. It is entirely written in core java. since it is under development so some may not work. The most exciting feature of sandeshvahk is click-to-call with no cost which is not in whatsapp is under development.