Dip is a project mainly written in JavaScript, it's free.
A Javascript-based Diplomacy web app
Directory tree: assets // image files, etc. css // cascading style sheets doc // documentation, specs, etc. js // third-party javascript libraries (e.g., Raphael) json // JSON data (e.g., board info) lib // game libraries temp // miscellany
Potentially useful libraries for future development:
Timers (for showing turn results with SVG animations) http://plugins.jquery.com/project/timers
Qtip 2 (for tooltips and dialogues) http://craigsworks.com/projects/qtip2/
Joint (cheap and easy arrows) http://www.jointjs.com/
jQuery-JSON (more reliable JSON conversion for older browsers) http://code.google.com/p/jquery-json/