CSS3 Framework With HTML5 Support: 52framework
52framework is a CSS framework which aims to provide an easy way to build websites using HTML5 & CSS3 while still supporting all modern browsers (including ie6).
It uses HTML5 tags like header, nav, section, article, footer or new input field types like url, email, etc. The framework also has a HTML5 compatible reset stylesheet.
52framework uses the new
::selection selector that enables you to customize the properties of selected text.
It can apply rounded corners for any block level element, text-shadow for text elements & more.
The framework also includes styles for creating grids: 16 column, 52 pixel based with 8 pixel gutter.
52framework is a user-contributed resource & you can easily send suggestions to improve it further.