The World Wide Web Consortium (W3C) is a consortium that produces standards—"recommendations," as they call them—for the World Wide Web. The Consortium is headed by Tim Berners-Lee, the original creator of URL (Uniform Resource Locator), HTTP (HyperText Transfer Protocol) and HTML (HyperText Markup Language), the principal technologies that form the basis of the Web.
A W3C standard goes through the stages Working Draft, Last Call, Proposed Recommendation and Candidate Recommendation. It ends as a Recommendation. A Recommendation may be updated by separately-published Errata until enough substantial edits accumulate, at which time a new edition of the Recommendation may be produced (e.g., XML is now in its Third Edition). Sometimes, a recommendation is withdrawn and sent through the process again, as RDF was. The W3C also publishes informative Notes which are not intended to be treated as standards.
The Consortium leaves it up to manufacturers to follow the Recommendations. Unlike the ISO and other international standards bodies, the W3C does not have a certification program, and many of its standards do not formally define levels of conformance. Consequently, Recommendations are often implemented only partially. The Recommendations are under a royalty-free patent, allowing anyone to follow them.
The Consortium's headquarters is at present on the fifth floor of the Gates Tower in the Stata Center at MIT. The other partners managing the W3C are ERCIM and Keio University in Japan.
W3C also engages in education and outreach, develops software, and serves as an open forum for discussion about the Web.
W3C also publishes various kinds of informative Notes which are not intended to be treated as standards.
The W3C has decided for now that it is not suitable to start such a program without the risk of creating more drawbacks for the community than benefits.
The W3C is not charged with developing standards for the Internet in general; this is more the role of the Internet Engineering Task Force, a separate organization with which the W3C cooperates on certain projects.
The W3C formerly described the coordination and separation between itself and the IETF, as well as partnerships with other organizations, in an appendix to its process document, though that information is now kept in a separate liaison list including all of its formal relationships with other organizations.
W3C Recommendations do accumulate errata and sometimes go into second editions which incorporate errata, so it's worth checking to see if there is errata or a newer version.