TestSwarm

TestSwarm provides distributed continuous integration testing for JavaScript. It was initially created by John Resig as a tool to support the jQuery project and has since moved to become an official Mozilla Labs project.

Much of the reasoning behind the original creation of TestSwarm is explained in the following:

• JavaScript Testing Does Not Scale
  
• and in the following recorded presentation
  
  The primary goal of TestSwarm is to take the complicated, and time-consuming, process of running JavaScript test suites in multiple browsers and to grossly simplify it. It achieves this goal by providing all the tools necessary for creating a continuous integration workflow for your JavaScript project.

Homepage: https://github.com/jeresig/testswarm