[khaled]

I can count like half a dozen TeX/LaTeX alternatives (SILE, Patoline, Platypus, Lout, some are more dead than the others) without even looking them up. It is easy to make a TeX/LaTeX alternative, it is hard to get people to use it.

And if you mean TeX formats, there are no shortage of these https://ctan.org/topic/format.

[jfk13]

> It is easy to make a TeX/LaTeX alternative

I'd rather say it is easy to start a TeX/LaTeX alternative. Completing one is another matter.

[khaled]

I strand by my comment. Replicate core TeX (and LaTeX) core features is easy (text layout, hyphenation, line breaking, math typesetting, etc. all are solved issue, often with many independent implementation that are as good as TeX‘s if not better), the issues that holds most people are packages and decades of TeX/LaTeX legacy.