The Dublin Core Metadata Initiative is an open organization engaged in the development of interoperable online metadata standards that support a broad range of purposes and business models.
Google Doctype is an open encyclopedia and reference library. Written by web developers, for web developers. It includes articles on web security, JavaScript DOM manipulation, CSS tips and tricks, and more. The reference section includes a growing library of test cases for checking cross-browser and cross-platform compatibility.
RDFa is an extension to HTML5 that helps you markup things like People, Places, Events, Recipes and Reviews. Search Engines and Web Services use this markup to generate better search listings and give you better visibility on the Web, so that people can find your website more easily.