[Discuss] What (free software) options are people using for chat?

[dsr at randomstring.org (Dan Ritter)]

$WORK needs secure chat, which means we must run the server and have a
fair amount of confidence in the clients. So we run an XMPP (ejabberd)
server, with SSL/TLS required and no open registration.

All the open source groups that I know (with no particular security
requirements) use existing IRC networks, mostly freenet.

There is one set of discussion groups I know that uses Slack; I use the
IRC interface to Slack to talk to them.

Random friends tend to use Google Talk/Hangouts, which has an XMPP
interface but doesn't federate.

Pidgin handles all these protocols smoothly, so I don't have to
think about which one I'm using except when I set it up.

-dsr-