Due to legal issues, The Coding Monkeys have renamed Hydra, their Rendezvous enabled text editor, to SubEthaEdit. I like the fact that the name is in honour of Douglas Adams but it doesn't exactly roll off the tongue does it? Still, it remains an excellent piece of software and has opened up a new realm of possibilities for collaborative development amongst Mac users.
Over the last few months, I've been learning GNU Emacs. Previous attempts at figuring out Emacs’ mind-boggling keystroke commands failed miserably until I found this excellent tutorial introduction. Yes, there is a steep learning curve involved in learning it, but in my opinion, it's worth it. I can access Emacs running on my Mac remotely from any machine (regardless of platform), do a spot of editing as well as check my Mail and Newsgroups. There are not many editors that allow you to do that.
So, because Emacs does everything you'd want an editor to do plus a million other things, I realised that it must have some kind of SubEthaEdit-like function for editing collaboratively. This command does something similar:
M-x make-frame-on-display host.example.com:0.0
OS X users can run GNU Emacs from the Terminal by typing ‘emacs’. Alternatively, there's a Carbon port available for Jaguar here (recommended).