It's true, I admit it, I have a bit of a thing for tabbed text editors (I'm seeking counseling). Anyway, I've discovered yet another one. Peter Borg (who is also behind the very cool Lingon launchd utility) has just released version 3 of his Smultron open-source text editor (with vertical tabs). This update improves a lot of things, including project management, application speed, memory usage, and not least of all, the interface (the tabs themselves are not new). Though I won't be dropping TextMate anytime soon, Smultron definitely looks like an interesting entry in the free text editor sweepstakes.
Smultron is a free download from sourceforge.