This document describes the operation and usage of the Quality of Design and the Content Checker Testing Tools. These tools were developed at the National Institute of Standards and Technology (NIST) to support people in developing standards for the exchange of data based on the Extensible Markup Language (XML) and the related standard XML Schema. The tools are web-based and provide a collaborative environment for users to develop tests of their data exchange specifications and data based on those specifications. Additionally, tests for some 3rd party guidelines for XML Schema are available through the web-based systems. This document is a user s guide for people using those systems either to develop their own tests, to use the tests that are available, or to augment the existing tests with their own.