W3C has announced the release of a new XML Conformance Test Suite that any developer can download free of cost and use to test an XML processor's conformance to the XML Recommendation. Built in cooperation with NIST and formerly hosted by OASIS, the XML 1.0 (Second Edition) errata 20020320, W3C Conformance Test Suite 20020606 contains over 2000 test files and an associated test report. The test report supplies background information on conformance testing for XML as well as test descriptions for each of the test files included in this release. This new XML test suite provides a set of metrics for determining conformance to the W3C XML 1.0 Second Edition Recommendation, and is intended to complement the W3C XML 1.0 (Second Edition) Recommendation dated 6-October-2000. All interpretations of this Recommendation are subject to confirmation by the W3C XML Core Working Group. Implementors are encouraged to write a harness around these tests to test their implementation for XML conformance."

From the announcement:

The XML 1.0 W3C Conformance Test Suite was developed in cooperation with NIST, and was formerly hosted by the Organization for the Advancement of Structured Information Standards (OASIS). The test suite contains over 2000 test files, and provides a set of metrics for determining conformance to the XML 1.0 (Second Edition) Recommendation. Both W3C's XML Core Working Group and OASIS' XML Conformance Technical Committee have contributed test cases. W3C recognizes the substantial value that cooperation among W3C, NIST, and OASIS has added to this endeavor.

Quality Assurance Activity Strengthens W3C Specifications: "The release of the XML Conformance Test Suite is the latest push by W3C's Quality Assurance Activity to promote interoperability on the Web. The Quality Assurance Activity helps other W3C Working Groups develop test suites and validation tools (listed in the W3C QA Matrix), and strives to improve the quality of W3C specifications. The XML Conformance Test Suites are free for any developer to download and use.

From the XML Conformance Test Suites Process Document: "A joint effort between W3C and NIST has been established to produce a highly comprehensive conformance test suite (XML TS) for the XML specifications. The XML 1.0 Second Edition Test Suite is being augmented to reflect the current work of the W3C XML Core Working Group. W3C will be responsible for assessing issues with the TS. NIST has agreed to allocate resources to update and maintain their current test suite to reflect the assessed and resolved issues. Also, the test suites will be jointly developed by these two parties and will take the form of a public framework... The XML TS aims at helping implementors to write applications that support the XML specifications. In no way are these conformance tests in the sense of providing companies or institutions with certification of XML support. The only claim that could be made is that a particular implementation is conformant to a particular version of the XML TS. There are two cases of results of running the test suite: (1) The implementation fails to pass the test suite. In this case it can be asserted that the implementation fails to meet the relevant XML specification. (2) The implementation passes the test suite. In this case all that can be asserted is that the implementation is conformant to that particular version of the XML TS..."