In January 2002, a group of programmers got together to produce an environment in which several Diplomacy AI's could compete. This environment was named the Diplomacy AI Development Environment (DAIDE).
The project has a fully established language syntax and communications protocol.
To support this project David Norman has created a diplomacy server (AIserver) and a human interface program (AImapper). This allows for games to be played between bots, as well as humans against bots, and finally all humans.
The AI Server is known to be well suited for human real-time (RT) games, with the added benefit that bots can fill in any missing positions. It works over simple TCP/IP protocol and has allowed players all around the world to easily conduct games.
For more DAIDE information, please visit the main site.
Furthermore, if you are at all interested in programming an AI, David Norman has created a c++ Client Framework that makes it very easy to get started and create a bot. All of the basic communications code and game information is readily available in the framework.
I was not involved in any of the establishment of DAIDE back in 2002. But it is the environment where bots can be made, and best of all compete.