Construct 2 - Scirra Construct is a 2D game development engine with a focus on building games visually.
Unity - The multiplatform game creation tools for everyone.
Godot Engine - Feature-packed 2D and 3D open source game engine.
BYOND - BYOND is the premier community for making and playing online multiplayer games.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Corona SDK - Cross-platform mobile app development.