Unity - The multiplatform game creation tools for everyone.
Shiva Engine - Shiva Engine is a cross-platform development solution.
Godot Engine - Feature-packed 2D and 3D open source game engine.
AndEngine - AndEngine is a free android 2D OpenGL game engine.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Kythera - Kythera is an AI middleware middleware plus development services with a complete solution for AI in games.