Autodesk 123D was a suite of hobbyist CAD and 3D modeling tools. Developed by Autodesk, Inc.
License: Free Personal
123D is more accessible and user-friendly, making it suitable for beginners, while Houdini is a professional-grade software known for its powerful simulation and VFX capabilities. While 123D focuses on modeling and basic animations, Houdini excels in complex simulations and effects.