More Jabber news
I've definately decided to go with the Jabber stuff I described earlier. A few more advantages:
Threading issues are simpler. If the users are responsible for re-establishing connections, there's a nasty time while the system is logging in, but the server will reject any other messages, like I said. If I take control of the re-establishment, it's easy to block these messages. There are also a few misc. places where I could construct a multi-threaded scenario where something bad happened; this reduces, and I think eliminates, those. (I need to double-check the elimination claim, but even if it's false, the consequences of being incorrect are not that critical.)