schema.org, a new initiative from Google, Bing and Yahoo for webmasters and developers

Working together Google, Bing and Yahoo!, they announced schema.org, a new initiative from Google, Bing and Yahoo! to create and support a common vocabulary for structured data markup on web pages. With schema.org, site owners and developers can learn about structured data and improve how their sites appear in major search engines. The site aims to be a one stop resource for webmasters looking to add markup to their pages.

Search engines have been working independently to support structured markup for a few years now.  Google  introduced rich snippets to Google search in 2009 to help people find better summaries of reviews and people, and since that time we’ve expanded to new kinds of rich snippets, including recipes and events. We’ve been thrilled to see content creators across the web—from stubhub.com to allrecipes.com—add markup to their pages, and now Google is able to show rich snippets in search results more than 10 times as 
often as when Google started two years ago.