Unity - The multiplatform game creation tools for everyone.
TripleA - TripleA is a free (under GPL) turn based strategy game based on Axis & Allies board game.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.
Warlight - Warzone is a customizable Risk-like strategy game where you compete with your friends to conquer the world.
Corona SDK - Cross-platform mobile app development.
Domination - Domination is a game that is a bit like the well known board game of Risk.