jDip is a Diplomacy™ adjudicator and mapping program that runs on Windows, Linux, Macintosh OS X, and Solaris.
It has a graphical interface for both entering and viewing orders. Orders may also be entered via cut-and-paste, or typed in directly. Games from email-based adjudicators (Judges) can be directly imported, and email results can even be added to existing games.
The automated adjudicator is very fast, very accurate, and supports the latest (2000) rules. Over 25 variants are currently supported.
If you are interested in helping the jDip development team, see the Contact page for more information.