I've been researching how to interact with the MSN messenger / Live messenger service programmatically and I can't find any real documentation on this. The documentation for the Live services only seem to implement in Javascript (they're here: http://dev.live.com/Messenger/)
It would be possible to reverse engineer this API to obtain the web services that it is actually using, but I am guessing that they didn't provide the sources for a reason (which means that those web services aren't meant for direct access).
However I can't find any other official APIs that allow programmatic access (more specifically no APIs that mention sockets, web services, or a proper programming language like Java or .Net).
Does anyone know if an API like that exists?
Check out LibPurple, which is the library underlying the pidgin multi-protocol IM client.