Robot Arena 2 is a video game that Jacob once played a lot, basically a Robot Wars emulator, where you built your robots, built their weapons, programmed the controls and beat up other robots with them. As a joke during LANFest III he added it to the porn folder and started playing it during quiet moments. Someone else saw this, downloaded and installed it, and joined in. Somehow, the game became a huge focus of that LANfest, probably beating Guitar Hero and AoE in cumulative hours played. After that LANfest no one ever touched it again.