Tinkercad online 3D design and 3D printing app
Tinkercad is used by designers, hobbyists, teachers, and kids, to make toys, prototypes, home decor, Minecraft models, jewelry – the list is truly endless!
Blender Open Source 3D creation
Blender is the free and open source 3D creation suite. It supports the entirety of the 3D pipeline—modeling, rigging, animation, simulation, rendering, compositing and motion tracking, even video editing and game creation.
SketchUp:3D modelling for everyone
SketchUp users are architects, designers, builders, makers and engineers. They are the people who shape the physical world. They are important, and they deserve great tools because great tools produce great work.
Open SCAD
A free 3D-modeling software for Windows, Mac OS, and Linux, Open SCADfocuses more on the CAD aspects of modeling an object rather than the artistic aspect. Unlike many others listed on this page, Open SCAD is not an interactive modeler but a 3D-compiler modeler that reads in the details of the objects to render their 3D models on the screen.
AutoDesk 123D
A suite of CAD and 3D-modeling tools, AutoDesk 123D even supports the 3D printing technology. AutoDesk 123D consists of various tools to create, design, and render 3D models. The websites also offers more than 10,000 free 3D models to get inspiration from, fun experiments, or for use in personal projects.
Netfabb
Supported for popular platforms such as Windows, Mac OS, and Linux, Netfabbis not just a viewer but can also allow its users to analyze, edit, and repair 3D models. It supports 3D printing, and is the smallest lightest tool amongst its competitors with regards to installation size. The size does not compromise on the features though.