When everything is running, this project lets a person describe a part in a small declarative language and watch it take shape in 3D. The demonstration models a parametric Lego-style brick, and the finished model can be exported as an STL file. The whole thing even runs straight from a web browser at play.mucad.org, which lowers the barrier to trying it a lot.
The way the brick is constructed stands out. The outer walls come from offsetting a base rectangle inward by a thickness constant, those walls are then combined with interior hollow support rings, and the assembly is extruded upward. The geometry lives in a reusable component that takes columns, rows and base height as parameters, and an array distribution operation fills the viewport with an 8 by 8 grid spanning 27cm. Named constants like spacing and tolerance appear throughout, and in my view that keeps a model easy to read and tweak.
Under the hood the compiler is written in Rust and emits a structure called the ModelTree, intended to be handed to any CAD kernel. That is a deliberate contrast with OpenSCAD, which the maker set out to rewrite and which carries a hard dependency on its built-in CSG kernel. Right now µcad has only a minimal CSG kernel, and an OCCT backend is planned to output solid models instead of meshes. Python wrappers built on PyO3 and maturin are planned too, along with a dedicated FreeCAD workbench.
One open problem the maker names directly: mapping visual edits back to code is difficult and has tripped up other projects. Feedback is being gathered on the syntax, the design workflow and which FreeCAD integration features would matter most, so there is a real opening to shape where this goes.