I built a zero-browser, pure-JS typesetting engine

This is exactly the kind of tool you didn't know you needed until someone built it. A film director who got sick of clunky screenplay software wrote his own pure-JS typesetting engine that takes custom Markdown syntax and spits out industry-standard PDFs — no browser, no bloat, just him solving his own problem. The fact that a non-dev built this in pure JavaScript is giving "figured it out anyway" energy, and if it actually handles mixed-language scripts well, screenwriters might actually have something worth switching for.