I just found out about PIE.htc, a javascript behavior file for IE that enables a lot of CSS3 on IE6+. I though of integrating it with my own css3hacks library to do all the work for ie. So today I just commited the library to google code. It is really simple to use. Just add a javascript file to your html:
Then write normal css3 like:
#my-box { border-radius: 5px; }
This will enable rounded borders on all browsers I could test: IE6, IE7, Firefox 3, 4, Chrome, Chromium, Opera various versions. Right now it supports just border-radius-* and variable definitions but I’m planning on adding support for more css3 rules in the future. You’re welcome to give suggestions, report problems or contribute code