Pentago is a favorite board game of mine, which I used to play regularly with coworkers during lunch (and occasionallyduring not-lunch). The rules are very simple, and casual games can be played in just a few minutes, but it's deep enough to still be satisfying if you're willing to put some thought into your strategy. In 2009 I wrote a computer player for Pentago in C#, and even managed to cobble together Silverlight and Windows Phone UIs for it that aren't terrible. The engine uses a negamax algorithm with alpha-beta pruning .
I put the engine up on Codeplex a long time ago, but never thought to publish the UI projects. This week I moved the whole thing to GitHub (UI projects included)and made sure it builds and runs with VS 2015. Things I hope to find time/motivationfor in the not-too-distant future: Re-implement the engine in F#, with various performance and design improvements Publish the phone version Make an HTML/JS front-end In the meantime, here's the Silverlight version to play with! [Note that if you're using Chrome you'll need to take extra steps to enable Silverlight.]