I had the pleasure of using SubEthaEdit today. Both myself and George needed to edit some text at the same time (literally!) and he mentioned that it was a shame that I didn't have a Mac, because we could use SubEthaEdit if I did. Well, as it turns out, I do have a Mac hanging around here.
I was a bit sceptical at first; I don't particular like Mac, even though OSX is not too bad. But, WOW, SubEthaEdit just works. I can see George typing stuff and his changes are in a different pastel colour from mine. What a great tool.
Now, why don't we have this tool for platforms other than OSX? Looking at their site, the SubEthaEdit people seem particularly elitist about it being Mac-only and they don't want to OpenSource it (fair enough).
It's tempting to start another one of my world-domination attempts by writing my own version of this app using, say, wxWidgets.