SolveSpace is a free libre and open source 2D and 3D CAD (computer-aided design) program. It is a constraint-based parametric modeler with simple mechanical simulation capabilities. Version 2.1 onward runs on Windows, Linux and macOS. It is developed by Jonathan Westhues and a community of volunteers.

Applications include:

1. Modeling 3D parts – Draw with extrudes, revolves, and Boolean (union / difference) operations
2. Modeling 2D parts – Draw the part as a single section, and export as a DXF, PDF or SVG; use 3D assembly to verify fit
3. Preparing CAM data – Export 2D vector art for a waterjet machine or laser cutter; or generate STEP or STL, for import into third-party CAM software
4. Mechanism design – Use the constraint solver to simulate planar or spatial linkages, with pin, ball, or slide joints
5. Plane and solid geometry – Replace hand-solved trigonometry and spreadsheets with a live dimensioned drawing

SolveSpace is free software distributed under GPLv3. Files to open need to be in its own text-based SolveSpace Models (*.slvs) format. Various export formats are provided, including 2D vector drawing as DXF, EPS, PDF, SVG, HPGL, STEP; 3D wireframe as DXF and STEP; triangle mesh as STL and Wavefront OBJ; and NURBS surfaces as STEP.

For more information:

https://en.wikipedia.org/wiki/SolveSpace