The Windows Internet Explorer Testing Center is a place Where you can verify Internet Explorer 9ís performance, standard support and other information against browsers.

One of the three key elements to a healthy standard is a comprehensive test suite. Without a rich set of tests that align with normative statements in a specification, the proposed standard is just a document on a website. Any browser can claim to support some or all of a specification but thereís no way to know whether each browser will render the same markup consistently. Web developers have told us that by seeing the test results, chapter-by-chapter, spec-by-spec, it enables them to spend their valuable time building rich web experiences for their customers.
Read more: Internet Explorer 9: Testing Center