ECMAScript 5 Conformance Suite is designed to assess the level at which a specific JavaScript implementation conforms to the ECMAScript, 5th Edition Language Specification. At the ECMA TC39 meeting this May, Microsoft announced that it was working on such test suite and made a preliminary version available to the ECMA members. We have now turned development of this test suite into a community development project hosted on Codeplex. This project is released as using the new BSD open source license and will be coordinated by TC39 members including Microsoft,” revealed.