"Google's security team is home-brewing a powerful combination scanner
and fuzzing tool that experts say will be unique outside of the
commercial domain.
In a posting on the Google security team's blog, Srinath Anantharaju
said on July 16 that the security team has been working on a black-box
fuzzing tool called Lemon, in the spirit of the word as it's used to
denote defective products.
Fuzz testing, or fuzzing, is a black-box software testing technique in
which malformed data is injected automatically to find implementation
bugs in code. In particular, Google is targeting XSS (cross-site scripting) bugs, according to Anantharaju."
Article Link: http://www.channelinsider.com/article/Google+Homebrews+Powerful+Automatic+Scanning+Fuzzer/211797_1.aspx