Because it doesn't support CSS Animations, which I use for insertion detection. I might be able to finagle it for IE9 with Mutation events, but in their DOM Level 3 state, they destroy performance.

IE10 supports CSS Animations and will also be the first IE version to support HTML5 Windows apps, those are the two most significant reasons it is the current minimum version for IE. If IE9 is the thing people really need, I can try to work it in, we'll see what folks say ;)

This really makes me sad. Mutation events gets you to IE9 but not 8, which means this cannot be used for enterprise apps. I'll start using it in personal projects though. Love the work.

Yeah the funny thing is I could actually even make it work in IE6 and 7 if I used Mutation for IE9 and then - ready your pitchforks and torches folks - proprietary CSS Behavior script ducks to avoid tomato. IE8 screwed the pooch in this regard - they removed CSS Behaviors but failed to implement anything that could be used to do the same sort of thing.

Do it, because without IE7 or at least IE8 support this will barely get used.

I'm going to work on it this weekend!