as someone mentioned recently somebody made this build123d-playground on the web:

https://jojain.github.io/build123d-sandbox/

learning curve is steep, but the examples get you going in no time..

though not really CAD, favorite example: https://build123d.readthedocs.io/en/latest/examples_1.html#c...

shows the ability of this implementation of the open cascade kernel.. i havent found this kind of projection function too often in other cad programs, so this is really cool.. i remember trying to do similar with ptc creo and it was a pain..