There's even a package (cmarker) than can translate Markdown to Typst which could be enough for a MVP.

We have responsive and open standards like HTML and EPUB (zipped XTML) and they work great. arXiv has HTML papers, and libgen and anna's archive often have EPUB versions of books. The issue for me with EPUB is the lack of good readers now.

I months into building a pasteboard transform library that normalises VS Code, Google Docs, PDFs and a bunch of Chromium apps provider-specific data so I can start pasting everything everywhere exactly how I want it. It's much, much messier than I expected.

Apps put different UTTypes on the pasteboard that are not really compatible with each other. Usually there's a plain text fallback, then rich text/HTML, then provider-specific data. You show how much insane work is needed just to make text selectable with glyph mappings, layout, links, code blocks, rendered styles, etc. But once you copy from that PDF, most viewers still only expose raw text, and often broken raw text at that...