While the link above talks about how to install SIP support for Empathy on Ubuntu (because, really, Ubuntu is Linux, isn’t it?), it’s easy enough to get working under Fedora as well.
yum install telepathy-rakia
That will install a bunch of depndencies, including sofia-sip.
Telepathy is to Empathy as libpurple is to pidgin, it seems, so I’m now in the process of getting familiar with the various Telepathy capabilities that are in Fedora’s package repository.
I’m also going to try this all in conjunction with a couple of different XMPP servers, including Prosody and ejabberd — because I’m not comfortable with continuing to put everything in the Openfire basket (although I’m still convinced Openfire is the best XMPP server out there right now).
With the latest batch of package updates (not to Empathy specifically, but other core libraries), I’ve been able to get Empathy to connect to my Openfire test servers with their self-signed certs. Empathy now prompts for the user to accept or reject the cert. If accepted, the client completes the connection. pulling in the user’s profile and roster.