IE7? Because it was so much better than IE6, that's the biggest reason. Still pretty much bites with some CSS though. Thanks for the mention, mouser!
I go through waves of changes to the list. I try to use an app for no less than an entire month (often exclusively) before adding it to the list, so adding them takes time. I really should "date" the list, by listing how long each app has been on it — 1, 2, 3,... years. As more Web 2.0 apps become established (not just "fantastic" startups), I'll be adding those over time, and the list will naturally change as more apps are written to take advantage of 64-bits. I've been asked a 100 times to create a GNU/Linux list, but I know so little about them that I'm not qualified to do so. Although, that might be a short list, ha!