RapCAD
What RapCAD is
RapCAD is a free integrated development environment for creating rapid-prototype models for RepRap and RepStrap 3D printing machines. It uses a modular scene description language instead of a graphical CAD workflow, with procedural and imperative instructions for defining and automating models. Text-based designs work with traditional source-control software, and reusable component modules can be distributed as design libraries. RapCAD handles 2D and 3D objects in the same environment and supports union, intersection and difference operations on 3D Nef Polyhedrons. Arbitrary-precision arithmetic is powered by GMP and MPFR, with conversion to floating-point precision during rendering or export. The software is designed to use multi-core processors for calculations. It runs on Windows, Ubuntu Linux and macOS; the README names Ubuntu Bionic, Focal and Groovy. The GPLv3 project is maintained by Giles Bathgate, and its scene language avoids file and network access capabilities.
Who it suits
RapCAD suits 3D-printing designers who prefer text-based, procedural modeling and source-control workflows. It is also intended for users creating reusable modules for RepRap or RepStrap projects.
What it does well
- Free GPLv3 software
- Text designs suit source control
- 2D and 3D objects together
- Boolean 3D geometry operations
- Windows, Ubuntu Linux and macOS
What to know first
- Uses a scene language instead of graphical CAD
- Ubuntu support lists specific distributions
- Rendering converts to floating-point precision
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| RapCAD | GPLv3 software; no paid plans or usage limits stated | Free |
As rapcad.org lists them, read 11 Oct 2026. The maker's own page has the final word.
Verdict
RapCAD offers a source-friendly, procedural approach to rapid-prototype modeling with 2D, 3D and Boolean geometry support. Its workflow is aimed at users comfortable defining models as text rather than through graphical CAD tools.
Facts from RapCAD's own pages
- 2D and 3D
- Users can work with 2D and 3D objects within the same environment. · rapcad.org, 11 Oct 2026
- Boolean geometry
- It supports Boolean operations on 3D Nef Polyhedrons, including union, intersection, and difference. · rapcad.org, 11 Oct 2026
- Design approach
- It uses a modular scene description language rather than a GUI based CAD workflow. · rapcad.org, 11 Oct 2026
- Free plan
- Yes · rapcad.org, 19 Sept 2026
- Integrations
- Designs are compatible with traditional text based source control management software. · rapcad.org, 11 Oct 2026
- License
- The project is published under the GPLv3 license. · github.com, 11 Oct 2026
- Linux limitation
- The README lists Ubuntu Bionic, Focal, and Groovy as supported distributions. · github.com, 11 Oct 2026
- Maintenance
- The project page says RapCAD is maintained by Giles Bathgate. · rapcad.org, 11 Oct 2026
- Multithreading
- RapCAD is designed to use multi core processors for faster calculations. · rapcad.org, 11 Oct 2026
- Precision
- RapCAD uses arbitrary precision arithmetic powered by the GMP and MPFR libraries, converting to floating point precision at rendering or export. · rapcad.org, 11 Oct 2026
- Procedural modeling
- Its scene description language supports a procedural and imperative approach for defining and automating model creation. · rapcad.org, 11 Oct 2026
- Purpose
- RapCAD is an integrated development environment for creating rapid prototype models for RepRap and RepStrap 3D printing machines. · rapcad.org, 11 Oct 2026
- Reusable modules
- Users can create reusable component modules and distribute them as a design library. · rapcad.org, 11 Oct 2026
- Security
- The project describes its GPLv3 licensed scene description language as avoiding general purpose capabilities such as reading or writing files and network access. · gilesbathgate.com, 11 Oct 2026
- Source control
- Its text based designs are compatible with traditional source control management software. · rapcad.org, 11 Oct 2026
- Supported platforms
- Installation instructions are provided for Windows, Ubuntu Linux, and Mac OS X. · github.com, 11 Oct 2026
Where RapCAD stands on Freedom251
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