Computer Diplomacy

This early rendition of the classic board game was popular when it came out, and I must admit, for a now freeware version released in the 1980's, it does the job. But it is still fairly lacking. There is actually no way to conduct diplomatic talks with the computer players, and overall the AI is somewhat poor. Occasionally you will find that they do in fact make good and unpredictable moves, however, persistence in this game really does pay off. For example, if you find yourself being dominated in the early game, play defensively and attack where you want repeatedly, turn after turn.

Eventually the AI will make a careless error (or several) and you're back in the game.
The interface is simple enough, although a mouse is not supported. Each territory is represented by a 3 letter abbreviation, and your armies and fleets show up on the map as miniature versions of your flag. To make moves, you type A for army or F for fleet, then type the land or sea region they are currently in, followed by the territory you wish them to go to. You can of course, do the more "complicated" actions of supporting and convoying (a fun little aspect of the game) by preceding the movement with an S for support, and C for convoy.
Overall, the single player experience was not this game's strong point. Unfortunately, I personally never played the computer version over a network or modem with several friends, as we had the board game. But that being said, the game engine is quite acceptable for multiplayer use, as you can send diplomatic messages to other players, and of course, have other players armies supporting yours in your endeavors.
However, with the recent release of a new diplomacy, with excellent graphics and a much better AI interface, even this games multiplayer capabilities fade into the background. However, it comes at a hefty price (even though the game has been out for over a year now, I believe), and if you're a fan of the original, and occasionally have a few hours here or there with nothing to do, this game still serves well as a time-killer.
In conclusion, unless you are a big fan of this game, and know the ins and outs of what you can and should do, I wouldn't recommend it, and even then, there is a much better version out that puts this one to shame.