A good program for editing code with another person on another computer

Question

What's a good program to edit code, or the same document at the same time with another person through the internet. I need something where a friend and I can edit the same document at the same but he's on a Windows computer and I'm on a Mac. Something like Google Wave where we can just create a wave and edit the document at the same time, but I want something for coding. It doesn't matter if we can't compile on the program just to edit it, and later we can save and compile on our computers.

Answer 1

I've used SubEthaEdit. It works quite well IMHO

Answer 2

I think you are asking for an IDE that allows multiple instances to open common files and projects. I don't think that exists.

However one lower-grade alternative might be to simply screen-share. One guy programming, the other guy kibitzing. This could be done in accordance with extreme programming (XP) rules: http://www.extremeprogramming.org/