[lyetzz]

I've been using Inspircd (http://inspircd.github.com) for quite a while, so I'd recommend checking that project out. As far as authentication goes, there's the Atheme (http://www.atheme.net) project that integrates nicely with Inspircd. If you haven't used it or heard of it, it allows you to register channels/rooms, establish a hierarchy of operators and admins, and give users the ability to login and secure their username.

Neither are the friendliest in terms of setting up and configuring, but it's really not too bad. If you have any questions, feel free to shoot me a message on IRC (irc.flux.cd #flux) or Twitter (@Lyetz) and I could help you out.