I am looking to have my client "react" to a received message through some xml based communications medium. I was looking into xmpp with google talk, but I just need something that can quickly relay messages on an event based basis (i.e. without having a thread over a "check messages" function.)
I am using twisted to do the rest of my project, so if at all possible, it would be very helpful to use twisted for the rest.
wokkel is an extension of twisted words that makes it super easy to develop clients and components.
Here is echobot as an example.