I came across Kod, a project run by Rasmus Andersson, by way of Daring Fireball:

Kod is a programmers' editor for OS X.

Currently under development, but will soon be available for dare-devil beta testing. "Kod" means "Code" in Swedish.

• Fully concurrent — loading files, syntax highlighting, etc is distributed across available CPU cores. Minimal waiting time.
• Integrated scripting environment based on Node.js.
• Written from scratch with modern OS X 10.6 APIs providing maximum OS integration while avoiding reinvention of the wheel.
• Sports a Chromium-like user interface where tabs can be torn off and moved between windows.
• Allows editing (although not saving, currently) remote files accessible over HTTP or HTTPS.
• Styling of the editor (not only the syntax highlighting) through regular CSS 3.
• Comes with support for over 65 different languages/syntaxes which can easily be edited or extended (Kod uses the same format as GNU Syntax Highlight).
• And more awesome features…

The beta is a real beta, with real flaws, but worth a look. It uses Sparkle for updates, so it's trivial to get new betas as they are released. An interesting UI feature is the use of a browser-like address bar. One use of the address bar is to see a nicely organized, syntax-highlighted change log, which you do by entering "kod:changelog".

When you get a Sparkle update a tab with the address "kod:changelog" automatically appears. Similarly, when you select "About Kod" from the app menu, you get a tab with the address "kod:about" that displays contact and licensing information, and third-party credits.

I didn't realize until I joined the mailing list how frustrated people are over the stagnation of TextMate. Kod is emerging in some people's minds as the answer to that, especially now that it's open source, using GitHub for its repository and Lighthouse for bug tracking.

Offhand I don't know of any Mac desktop app this ambitious that's used this open development model. It's been neat watching the discussions over the last few days. Rasmus seems committed to making the best development decisions he can, and providing the high level of leadership such a project will require. I'm optimistic, and surprised the project hasn't gotten more attention. Maybe after the holidays we'll see more about it in the blogs.

"Kod", by the way, is pronounced roughly like "code" in English. I don't know if I can get that Swedish "o" quite right. It sounds like it has a teeny extra syllable at the end.

Is the open source world big enough for two web-inspired Rasmusses? Stay tuned and see.