Features included the ability to search using operators, namely 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.

[1][2] The site allowed the use of regular expressions in queries, which at that time was not offered by any other search engine for code.

[citation needed] This makes it resemble grep, but over the world's public code.

In January 2012, Google developer Russ Cox published an overview of history and the technical aspects of the tool, and open-sourced a basic implementation of a similar functionality as a set of standalone programs that can run fast indexed regular expression searches over local code.