I've just developed a war game. It's one of my hobby projects for the past few years. Finally, I got it done. I named it Deep Battle. It is an abstract war game that models modern military strategy principles. It can be viewed as a cross-breed between classic Chess and Go, but in the modern setting of joint land, sea & air warfare.
It's written in Java, so it runs on all platforms supporting Java. You can download it at
http://www.decisive-options.com/node/102
It's completely free. Give it a try, let me know what you think. Hope you will enjoy it.