The Internet Explorer 9 Guide for Developers provides a look at the features and improvements in Internet Explorer 9 Release Candidate.

Enables <video> tags in all major browsers.

Modernizr uses feature detection to test the current browser against upcoming features like rgba(), border-radius, CSS Transitions and many more.

Tripoli is a generic CSS standard for HTML rendering. By resetting and rebuilding browser standards, Tripoli forms a stable, cross-browser rendering foundation for your web projects.

Mosquito can automate the most work for you! It can traverse through your site, enter data into fields, press buttons, and take screenshots according to user written script. All you have to do is look through already-taken screenshots to see if there are

Sahi is an automation and testing tool for web applications, with the facility to record and playback scripts. Developed in java and javascript, this tool uses simple javascript to execute events on the browser. Features include, in-browser controls, text

Selenium is a test tool for web applications. Selenium tests run directly in a browser, just as real users do. And they run in Internet Explorer, Mozilla and Firefox on Windows, Linux, and Macintosh.