if you’re into developing clients for jabber, and who isn’t – really – then you just might like, The Jabber Client Developer’s Cheat Sheet
“This is an informal tutorial guide for the perplexed developer trying to implement a Jabber client from scratch. Two weeks ago that developer was me; now, after many experiments and confused e-mails to jdev, I’m dropping pearls of my great wisdom to help you out. You’re welcome!”