Blender

Blender has been in development since 1994 and open-source since 2002. It runs on Windows, macOS, and Linux, and it is genuinely free — no upgrade tier, no enterprise lock, no asset store tax. The Blender Foundation funds development through grants and direct corporate sponsorship from Epic, Microsoft, AMD, NVIDIA, and others.

Official site: blender.org.

For 3D printing, Blender is the de-facto mesh editor. The built-in 3D-Print Toolbox (Edit → Preferences → Add-ons, enable "3D Print Toolbox") flags non-manifold edges, checks volume, and exports to STL with one click. The Decimate, Remesh, and Boolean modifiers handle most repair and edit tasks.

For artists, Blender competes with Maya, 3ds Max, ZBrush, and Houdini in different domains. It is not always the best at any single task, but it is good enough at most of them and free. The 4.x release line (2023+) modernized the interface and shifted Blender from cult tool to industry standard.

Blender's default keymap is unusual — right-click select, numeric pad navigation. Modern installs default to industry- standard left-click select; switch in preferences if it does not.

Blender is not a CAD tool. For parametric, dimensioned design you want Fusion 360, Onshape, or FreeCAD. Blender works with mesh primitives — moving vertices, not editing parameters.