usd-brep

USD BRep is NVIDIA's newly opened CAD geometry engine: it builds exact NURBS solids, not triangle meshes, and runs booleans, fillets, sweeps, offsets and tessellation on them. Solids go in and out as OpenUSD, the 3D scene format behind Omniverse. C++ and Python, Apache 2.0, free.

pip install usd-brep gets a CPython 3.12 wheel for Windows or Linux (x86 and ARM) with OpenUSD bundled. No macOS wheel. Source builds need Git LFS, Visual Studio's 2019 toolset on Windows and NVIDIA's repo tooling. One trap: never install PyPI's usd-core 25.11 alongside it; NVIDIA says importing both crashes.

Versus OpenCASCADE: OCCT is LGPL, far more mature, and ships STEP and IGES translators, which most CAD pipelines need. USD BRep's Python package has no STEP or IGES importer. Pick USD BRep if your pipeline already lives in OpenUSD or Omniverse; otherwise OCCT, or CadQuery on top of it. Free at every team size.

The catch: it's a week-old 1.0 that accepts no outside code contributions. The first issues filed report kernel bugs: a boolean union silently dropping a body, a fillet that hangs, one that corrupts a different solid, results that change between runs. Maintainers are responding. Treat it as promising, not proven.