Another fun fact: For Negatus to be able to run firefox for the tests, it has to run it in a display. Without setting up a fake X session, the Negatus client has to be logged in, at least on Linux. I am sure that this will be true on other platforms as well. For Linux, we could run in a virtual frame buffer, but I am not sure that this is necessary. Just set up the account the test will run in to auto login. Make sure it is on a private network, though...