This project evolved out of another open source project of mine (https://gridfinitylayouttool.com/designer) where I wanted to offer a great (and free) tool to generate models for 3D printing.

Its strengths are in parametric parts and architecture. Think OpenSCAD, but in familiar Typescript rather than a custom DSL. It's also based on b-rep topology so shapes are exact mathematical boundaries, measurements are precise, and STEP export is fully supported.