For various projects I’m doing right now, I need an easy way to automatically run code in an X server that may not necessarily be the active display. This code may even run on servers in production that don’t have video cards or monitors attached. For some history on this, check out this post on xvfb and firefox. You can solve the problem in that post by simply launching firefox with the tool below, and your X server will exit when firefox exits.

Resig has a bunch of unit tests he does to make sure jQuery works properly on whatever browser. Manually running and checking unit test results is annoying and time consuming. Let’s automate this. Update (May 2010): See this post for more details on automating xserver startup without having to worry about display numbers (:1, :2, etc). Combine something simple like Firefox and Xvfb (X Virtual Frame Buffer), and you’ve got a simple way to run Firefox without a visible display.