API for Yahoo Instant Messenger?

[Steve Canfield]

Does anybody know if there is a way to programmatically send/recieve
instant messages?  I have a small python program that can email me
files from my computer at work if I send it a message that looks
something like:
  <vss project='$/My Project'>
    <checkout>file1.cpp</checkout>
    <checkout>file1.h</checkout>
  </vss>
The above email would checkout file1.cpp and file1.h from our source
code control system and email them to me.

I have it set up to run every couple of minutes, but I was thinking it
would be much better if I could piggyback on Yahoo Instant Messenger
(or any other IM client).  Is there an API available for any of the IM
programs that I could use?

-steve