And interestingly "the oldest known public version-controlled codebase in the world that's still under active development" dating back to 1979.

[1] https://en.wikipedia.org/wiki/BRL-CAD#toc-History

Do you have any preferred guides for getting started wtih BRL-CAD? I've tried a couple of times, but it seems like it's more a large collection of various tools and it's hard to know where to start. Or even what the general design philosophy is. It looks like the core functionality is more a code-driven approach to modeling? With UI driven design (archer) only in the experimental/early-development stage?