popkern

popkern positions itself as a parametric boundary-representation geometry engine for solid CAD, built for people who make things and prefer expressing designs as code. Rather than a full graphical CAD application, it is a kernel: the underlying geometry layer that handles booleans, fillets, sweeps, shelling, and STEP import/export. It is free, open source, and written in Rust, with the stated ambition of becoming one of the best kernels available.

The core feature set centers on script-driven modeling with interactive editing, backed by research-class CAGD algorithms. Fillets are designed with properly smooth corners, and the project emphasizes watertight results, as shown by example models such as a six-axis arm with over a thousand features and dozens of parts. Real threads, planetary gearboxes, and cycloidal joints are all computed in script, demonstrating precision at the feature level. STEP support and MCP integration extend its use into broader workflows.

popkern is aimed at developers, computational designers, and makers who are comfortable writing code to define geometry. It also serves as a practical entry point for anyone curious about CAD kernels, since the browser demo lets visitors open an example and see the same script rebuild the same model instantly. Teams evaluating open-source geometry engines for custom tooling may find the one-line install and documentation useful.

To get started, try the live browser examples to understand the scripting model, then in