Gabriele periodically visits the continuum-B of the multiverse to chase obscure vernacular languages across the underground of Italian linguistics. (The time spent inside what I suppose is the continuum-A is devoted to chasing obscure programming languages across the underground of the Internet.)
I have the unfortunate tendency of listening, reluctantly but closely, to crazy people, so when he tells me “you should implement OpenID via XMPP in Firefox”, I reply “forget it, I don’t have the time”. A couple of evenings later, I’m trading two hours of sleep for a basic implementation. Oh well.
The package for Firefox and Flock is here (XPI install, 4KB) and the darcs repository is here. You’ll probably want to use this with SamePlace, but the only strict prerequisite is xmpp4moz. Update 2007-05-25: This is now available as a scriptlet! (What are scriptlets?)
I tested it with the page at xmpp.za.net. Load the page, enter your Jabber ID or GMail address (the latter apparently needs the full ID, e.g. firstname.lastname@example.org/SamePlace), make up a transaction identifier (e.g. “riffraff”) and soon you should see a confirmation dialog pop up and ask for your authorization.
At this time, the whole source is just one page long, so if you’re thinking of hacking it, have no fear and go ahead.
Update: For those who can read Italian, Gabriele has written a nice article about this for the Italian OpenID blog. There I learned that using XMPP in this context gives a serious stab at the issues with phishing usually brought up about OpenID. Cool!