Godot Engine - Feature-packed 2D and 3D open source game engine.
Unity - The multiplatform game creation tools for everyone.
MonoGame - MonoGame is an open source implementation of the Microsoft XNA 4 Framework.
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!
ct.js - ct.js is a 2D game editor (desktop app) based on web technologies.
Unity3D - Unity is the ultimate game development platform. Use Unity to build high-quality 3D and 2D games, deploy them across mobile, desktop, VR/AR, consoles or the Web, and connect with loyal and enthusiastic players and customers.