So happy to see new texlive as well
[1] https://www.latex-project.org/latex3/
[2] https://github.com/latex3/latex3
https://wiki.contextgarden.net/
It's a monolithic kernel with a relatively sane collection of "setup" macros that, by and large, can accomplish much of what LaTeX and its packages can do.
If you're curious about how to build TeX from scratch, have a look at my TeX.SE answer:
https://tex.stackexchange.com/a/576314/2148
I'd imagine making a FOSS port in Rust that has non-cryptic error messages wouldn't be a multi-year project using modern GPTs.
deep1283•2h ago
dngray•1h ago