@Ryan: Good ideas! I too thought the stacked tab (not using S&T, tried to simulate it manually :)) looked too attached to the main window, so I updated my mockup before I read that you had made another one too :) So this one's pretty much similar to Ryan's, except the yellow tab gradient is adjusted a liiiiittle :P I also incorporated Alex' idea of adjusting the icons. http://www.oljud.se/files/haiku/4_dark_act_border.png I also fixed a mistake that's been on most of my mockups - the yellow tab went one pixel too far down so it overlapped the border. And here's the original if you want to do side-by-side comparisons: http://www.oljud.se/files/haiku/0_haiku.png @Matt: Could be a cool idea if the border turned yellow when moving or resizing. Not sure if it would add anything, except aesthetics, but it would be fun to try some day. @Eddy: I have to go with Ryan on this one, I'm pretty sure it's an optical illusion. However maybe it's something we could try photoshopping. By faded, do you mean less saturated (more gray) or lighter/darker?