Having the same markup work correctly across the web requires comprehensive tests that all browsers can rely on to deliver interoperable implementations. Microsoft has worked with the W3C to provide definitive test suite specifications for HTML, CSS, SVG, and other web standards. In recent months, we’ve contributed nearly 200 new tests to the W3C for these standards.
That’s why Microsoft is now working with other browser vendors and other members of TC-39 to create an official test suite for ECMAScript sponsored by ECMA. We plan to help build this test suite, and contribute tests to it. We also welcome other browser vendors’ contributions to this effort.
Ensuring the same script works everywhere is vital to web developers. We look forward to hearing your feedback as we can continue to work on making this a reality.