Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Unity - The multiplatform game creation tools for everyone.
SelfCAD - SelfCAD is an online 3D modeling and slicing software.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.
Clara.io - Free online 3D modeling software: Design, editor, animation, rendering, & lots of free 3D models. Supports Three.JS, Blend, FBX, OBJ, V-Ray, Babylon.JS, STL.
Shiva Engine - Shiva Engine is a cross-platform development solution.