About This Service

The W3C HTML Validation Service checks HTML documents for conformance to W3C HTML and XHTML Recommendations and other HTML standards. Related resources include:

• Source code availability.
• The TODO list for The W3C HTML Validation Service.
• DTDs (document types) supported by The W3C HTML Validation Service (the SGML catalog).
• The www-validator mailing list.
• How to provide feedback on The W3C HTML Validation Service.

Other resources

Credits

The W3C HTML Validation Service was created and is maintained by Gerald Oskoboiny. In a previous incarnation it was known as "The Kinder, Gentler, HTML Validator", but has since found a new home at the W3C Systems Team where Gerald still slaves away at it.

This service uses:

• A derivative version of James Clark's excellent SGML (and XML) parser SP. The version in use for this service is the "OpenSP" version from the OpenJade team. For some time it also made use of Liam Quinn's modified version, lq-nsgmls.
• The LWP Perl Modules by Gisle Aas and Martijn Koster for retrieving documents.
• Documentation and Error Explanations originally written by Scott Bigham.
• Open source software including Apache, Perl, and Debian GNU/Linux.
• Patches and ideas from:
  • Aaron Swartz
  • Christian Smith
  • Dan Connolly
  • Hugo Haas
  • Jim Ley
  • Karl Dubost
  • Liam Quinn
  • Martin Dürst
  • Nick Kew
  • Olivier Thereaux
  • Sean B. Palmer
  • Terje Bless
  • Ville Skyttä
  • ...and the nice people on www-validator@w3.org.