Google Code Search

Google Code Search was a free beta product from Google which debuted in Google Labs on October 5, 2006 allowing web users to search for open-source code on the Internet. Code Search was officially shut down along with the Code Search API on January 15, 2012 but remains available for an unknown period of time. Features included the ability to search using operators. These are lang:, package:, license: and file:. The code available for searching was in various formats including tar.gz, .tar.bz2, .tar, and .zip, CVS, Subversion, git and mercurial repositories. The site allowed the use of regular expressions in queries, which is not offered by any other search engine for code. This makes it resemble grep, but over the world's public code....