jitsi-bin : Secure IM communicator that supports SIP, XMPP/Jabber, AIM/ICQ, Windows Live, Yahoo ( https://jitsi.org/ )
slack-desktop-bin : Official Slack Desktop Client ( http://www.slack.com/ )
spark : Spark is an Open Source, cross-platform IM client optimized for businesses and organizations ( http://www.igniterealtime.org/projects/spark/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a y2kbadbug
For Paludis use this rsync : rsync://gentoo.zugaina.org/y2kbadbug-portage
If you have a problem : ycarus(-at-)zugaina.org