Blender is free and open-source 3D animation software that can be used to create animated films, visual effects, 3D models, and video games. It includes tools for 3D modeling, UV unwrapping, texturing, rendering, particle simulation, fluid simulation, and animating. Blender was originally created as an in-house tool and has since been used for commercials, NASA 3D models and simulations, and the first major professional use was for pre-visualization on Spider-Man 2.