We love Skype, but really hate its group chat feature. IRC had a few issues, but we think we've worked them out. We now have an IRC channel for use.
Join us on Freenode on #Cosmos-Dev irc://irc.freenode.net/Cosmos-Dev
For a list of free and non free IRC clients, see here.
Most users are still using the skype chat room. IRC testing had some issues initially. We have worked through most of them. IRC is nice in that its easier to join and users can choose from a variety of clients. IRC though is more work to administrate (except joining), and does not keep history without requiring users to connect to or run bots.
We are working to phase out our Skype chat room, but many of the users are still there and for the time being it is far more active than the IRC channel.
You will need Skype installed to join our chat room. We use Skype because it is lightweight, non intrusive, not filled with ads, and most of our members already have it.
With the release of Skype 4.0, Skype has disabled public link functionality to chat rooms. They have stated that it will be added back in the future. Until then, please add user mterwoord who can then add you to the chat room.