Psi

... Adium does Jabber as well ... Adium does part of Jabber, to the extent you can use it to log in to a Jabber server and talk to other Jabber users. Adium does not, however, support some features of Jabber/XMPP, like service discovery. So if you're using XMPP transports for sAIM and Yahoo interoperability and want to use Adium, you have to find a client that supports transport discovery (like Psi) to set up your contacts. There are other services besides the gateway transports, too: multi-user chat, the Jabber User Directory and at least one presence server. My understanding is that libpurple/Pidgin (hence Adium) will get transport discovery/registration in the future, but Psi's been doing it for a while. Jabber.org used to have a client comparison chart, but it seems to be missing now. That's a shame, because it provided a good way to see which clients offered the very best support for XMPP, vs. "you can chat with it." Oh, Psi also supports PGP (or at least GnuPG) encryption. Some people are heavily invested in that, and Adium does not yet support it. ... and is Universal. Psi is also a Universal app. They need to update the information. I've got the current version sitting here in my apps folder and it's a UB. Psi is a bit of an odd fit on the Mac, because Qt apps have that same "this isn't quite right" feel that Java apps are often accused of having. But for a Jabber/XMPP user who is heavily invested in all the features XMPP offers, there's not much choice on the Mac besides, perhaps, Spark from Jive.

Yes, Adium is a nice IM client, but that doesn't mean it has to be the only one. PSI isn't as customizable or "pretty" as Adium, but it is a good client. Stop being so demeaning towards other programs. Calling Psi "a class project" is insulting and inappropriate. Adium has its own problems and I prefer to have alternatives. Thanks, Psi developers.

Also, Adium requires 10.4 these days.

Precisely my own thinking, when I decided to get a Dell instead of a Mac.