Test-definition is XML schema for validating Test plan xml files. It also contains schemas to validate results written by testrunner-lite.
The currently used schemas can be viewed from gitorious
tm-terms: http://gitorious.org/qa-tools/test-definition/blobs/master/data/testdefinition-tm_terms.xsd
Syntax: http://gitorious.org/qa-tools/test-definition/blobs/master/data/testdefinition-syntax.xsd
Results: http://gitorious.org/qa-tools/test-definition/blobs/master/data/testdefinition-results.xsd