This year
2010
operasoftware/operawatir - GitHub
OperaWatir is a part of the Watir (pronounced water) family of free software Ruby libraries for automating web browsers. OperaWatir provides a querying engine and Ruby bindings for a backend Java library, OperaDriver, for driving the Opera web browser. It aims for full compliance with the watirspec specification.
2009
Linux.com :: Using free software for HTTP load testing
A good way to see how your Web applications and server will behave under high load is by testing them with a simulated load. We tested several free software tools that do such testing to see which work best for what kinds of sites.

