QuirksMode.org is the prime source for browser compatibility information on the Internet. It is maintained by Peter-Paul Koch, mobile platform strategist in Amsterdam, the Netherlands.
QuirksMode.org is the home of the Browser Compatibility Tables, where you’ll find hype-free assessments of the major browsers’ CSS and JavaScript capabilities, as well as their adherence to the W3C standards.
It is also increasingly the home of ground-breaking mobile web research.