Quassel IRC is a modern, cross-platform, distributed IRC client based on the Qt4 framework. Distributed means that one (or multiple) client(s) can attach to and detach from a central core that stays permanently online -- much like the popular combination of screen and a text-based IRC client such as WeeChat, and similar to (but much more featureful than) so-called BNCs. More info »
I may have dismissed this too quickly, but I think you have to sign up for an account at quassel-irc.org before being able to connect to IRC. Not happening. Too bad, it looked like a decent interface. I recommend LimeChat...
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