No official information exists, but to aid with the development of the Pidgin IM application, the Pidgin devs have realeased an unofficial protocol spec:

http://developer.pidgin.im/wiki/MsimProtocolSpec

 (I couldnt get the page to load on my comp right now for some reason, hopefully it works later.)

 As a side note, this forum is about discussing Myspace Apps. If you need any more help, I'm sure there are people at the Pidgin forums who already have experience in the subject who could help you (I sure couldnt :P)

Yes I am looking for documentation also.

Looks like the specifications are now stored in a new location:

http://imfreedom.org/wiki/index.php/MySpaceIM

This is kind of a crazy coincidence.  I've been writing a chat client for the MySpace chatrooms for the past few months as a weekend affair (link:  http://mspc2.no-ip.org:8080/).  This is for the UserPlane rooms, not the MySpaceIM rooms, though.

Anyone know how I can get into contact with someone at myspace?  I'd like to increase the promenance of this app but I don't know how.

 Hello Jason. Would you provide me some information about the Myspace Chat API ? I need to know how can I send a message from my application. Thank you very very much!

 To the random myspace members posting in this thread, PLEASE STOP. 

This thread is about some devs talking about this concept. It's NOT a chat thread.

Rhonda

 LOCKING THREAD.

I've had enough of deleting posts from this thread.