syntax.whatwg.org syntax.whattf.org

This server hosts the syntax definitions for HTML 5, currently implemented in RelaxNG+Schematron. The original RelaxNG framework and Core modules were designed and written by fantasai. Henri Sivonen has add Web Forms 1 and 2 and HTML5 features. A web-based validation service using this schema is available.

Version control is provided at Bitbucket. A mailing list tracks changes to the code. Mercurial access is also available:

hg clone https://validator@bitbucket.org/validator/syntax