Chris Babcock (a Judge wizard as well as a skilled Diplomacy player and an all-around good guy) replied to a post on rec.games.diplomacy recently in answer to a question about how one would go about setting up a Judge server.  I thought his reply might be of interest tio some blog readers:

The hardware requirements are trivial. The judge software and other
information is available at http://njudge.org/. It runs on *nux. Your
options there are to set up an old PC as a Linux host on your home
network, change your workstation over to Linux, get a Power PC with
OSX or see if you can compile and run the judge under cygwin. The main
obstacle most users will have is that the judge is a server; Operating
one with a residential Internet connection is almost always in
violation of the Terms of Service of your ISP. For a private judge,
mail volume will probably not get high enough to be an issue, but a
public judge can kick out 500 emails during the 11 o'clock hour when
it's active.

The main thing is to think about the reason that you want to run a
judge and determine whether it's worth it. If you just want to GM a
lot of games, you can spread them out over a couple judges - USAK,
USAL, USAZ and UKYS, to name a few. If you want to run private games,
it's easy enough to do on exiting judges.

The best reason to start a new public judge is to serve a perceived
need. Serving different world regions (time zones and Internet
backbone connectivity) or serving different languages would be a
couple good examples. For a private judge, participating in judge
development or having total access control (to limit participation to
club members, for example) are the most common reasons.