eqn (part of troff) from 1974, predating TeX, had a very decent syntax! It's not as complete as TeX, and the layout quality is worse, and I wouldn't want to tou

eqn (part of troff) from 1974, predating TeX, had a very decent syntax! It's not as complete as TeX, and the layout quality is worse, and I wouldn't want to touch the rest of troff syntax. So not really practical, but good inspiration. Open/LibreOffice math formulas use a syntax that's clearly inspired by it. Unfortunately it's very lacking in documentation. Another important question is are you looking for presentational or semantic math? For presentational fine tuning I'm afraid nothing can beat the flexibility of TeX combined with a huge body of Q&A (on stack exchange and elsewhere)...