W3C:

2008-09-10: The Cascading Style Sheets (CSS) Working Group has published a Working Draft of CSS Backgrounds and Borders Module Level 3. CSS is a language for describing the rendering of structured documents (such as HTML and XML). This draft contains the features of CSS level 3 relating to borders and backgrounds. It includes and extends the functionality of CSS level 2. The main extensions compared to level 2 are borders consisting of images, boxes with multiple backgrounds, boxes with rounded corners and boxes with shadows. Learn more about the Style Activity. (Permalink)