CSS library (ex:Bootstrap) that supports IE6?

Check out HTML5 Boilerplate, a rock-solid default for building sites using HTML + CSS + JS.

I had a small degrade on a site we have that uses bootstrap on IE 7 and 8, but IE 6 was just awful. I applied the CSS on the Bootstrap-IE6 project and it looks pretty like IE 7 now. It's not perfect but a massive improvement on what I had.

Have you tried Grid 960?