See mailing list thread "Using Hudson in productive environment". Some builds
need to do GUI tests and need a graphic display. Running Hudson with a test
display is always possible, but cumbersome to set up, and limits you to one
executor (otherwise tests can interfere with one another if they grab focus at
the wrong time etc.). The suggestion is:

1. Have a checkbox (off by default) in project config to run jobs in a dedicated
display. Also have a pulldown for display type, including at least (according to
availability):

• VNC
• X
• Xnest

2. If set, start a new display for the duration of a job run. For X11-based
systems, set the DISPLAY environment variable. (I do not know if there is any
equivalent for Windows servers, or for Mac OS X. But should work fine on Linux
and other Unix variants.)

3. In the case of VNC, a cute trick (license permitting?) would be to use

http://www.realvnc.com/javavncviewer.html

to show the live display on the job's page. My Fedora Core system has this as

/usr/share/vnc/classes/vncviewer.jar

which curiously is part of the 'vnc-server' RPM, not vnc; it seems to be a Java
main class, not an applet, but this should be solvable (at worst by serving a
.jnlp file for it). Maybe Maven has the right JAR somewhere.