If you’d like to know how your browser scores for its CSS3 support, you have to check out Lea Verou’s CSS3 Test. She announced the project yesterday on her blog.
Here’s screenshot of my browser, Google Chrome 23.0.1271.101.
Lea actually planned this as an improvement to her interactive CSS playground called Dabblet (Source on GitHub), but it didn’t work out the way she planned, so she released CSS3 Test on its own.
If you haven’t yet, read her blog post about the project - she talks about how it works, using browserscope, how it doesn’t work on dinosaur browsers like IE8, and why she built it in the first place.
A word of caution the CSS3 test checks which CSS3 features your browser recognizes, not whether or not they are actually implemented correctly. Oh, and WebKit claims to support CSS3 background-repeat, but it is LYING.
If you’d like to add tests to CSS3 test, go to tests.js and follow the current structure. Also, there are lots of great conversations and comments about the project on Hacker News.