XML(JSON?)-over-HTTP: How to define API?

[Allen Fowler]

I have an (in-development) python system that needs to shuttle events / requests around over the network to other parts of itself.   It will also need to cooperate with a .net application running on yet a different machine.

So, naturally I figured some sort of HTTP event / RPC type of would be a good idea?

Are there any modules I should know about, or guidelines I could read, that could aid me in the design of the API?    


Thank you,
:)