Twist can be run on a box that does not have a display using Xvfb (http://en.wikipedia.org/wiki/Xvfb).

Follow these steps.

1. Install Xvfb
2. Start Xvfb server with the following command
            sudo Xvfb :1 &
3. Set the display to :1
            export DISPLAY=:1
4. Now you can execute the Ant target to run Twist scenarios
            ant execute-scenarios


Note: Sometimes, when starting Xvfb with the command described in step 1, the following error is thrown:
         could not open default font 'fixed'

If this error occurs, start Xvfb by running the following command:
           sudo Xvfb :1 -fp /usr/share/fonts/X11/misc &