Godot Engine - Feature-packed 2D and 3D open source game engine.
MonoGame - MonoGame is an open source implementation of the Microsoft XNA 4 Framework.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.
RPG Maker - Make your own PC game with RPG Maker. Our easy to use tools are simple enough for a child, and powerful enough for a developer. Try it free today!
BYOND - BYOND is the premier community for making and playing online multiplayer games.
Blacksmith 2D - Black is a highly optimized 2D framework for web, mobile games, and playable ads.