Facebook's own servers are supposed to handle XMPP chat traffic, and they have instructions for signing in with Pidgin, the client I'm using. Regardless, it's not working. I receive messages, but can't send anything back. The most frustrating part was that it didn't look like it failed - there was no delivery failure response, just silence. I'm pretty sure I did everything right, and it's not like this is some third-party workaround with plugins and external servers. This is signing into Facebook servers with instructions they provided. Maybe I just caught it on a bad day or something.
Mokalus of Borg
PS - It sure would be nice if chat systems were reliable.
PPS - Most of them are, I guess.