Multiplayer-Gaming-Framework--Client- is a project mainly written in Java, it's free.
Multiplayer Gaming Framework: Client by Philip De Smedt & Gino Wuytjens
This MGF Client can be used to communicate to an MGF Server (Apache or Google App Engine).
How it works
Using a set of endpoints, the client is able to send SOAP messages to the server. Typical messages for the framework are join, leave and status. A status reply contains all status updates the server registered since the last status message.