google-search
<entry-title>Google Search</entry-title>
Google is one of several search-engines that index and support microformats.
main search
Google.com supports rel-nofollow (since 2005(?) citation needed) and as of 2009-05-12, hCard, hReview, hReview aggregate, hProduct in rich snippets in search results.
See google-rich-snippets-examples for documentation of Google's microformats examples (along with a few corrections/improvements). See Jeni's blog post on What’s wrong with Google's RDFa Support for a description of the numerous problems in the *RDFa* documentation/implementation of "rich snippets". (to-do extract these instances of real world problems, analyze for causes, and note principles and techniques for avoiding them in the future.)
advanced search
Through additional user interfaces:
- Google Advanced Search - Usage rights supports rel-license (since 2005(?) citation needed)
search APIs
Google provides search APIs like:
- Google Social Graph API supports XFN (launched 2008 February). See "Google Social Graph API How are your sites connected?".