pyHanko VS xournalpp

If you mean signing as in "adding a digital, cryptographic signature", you could use pyhanko () which provides everything state-of-the-art to do just that.

Document read from codimd-api https://github.com/hackmdio/hackmd-cli/blob/master/README.md - Matching config.yaml + styles read from git - Fetching data from CRM https://docs.espocrm.com/development/api/#client-implementations - Parsing markdown as jinja template - Generate pdf from markdown https://github.com/jmaupetit/md2pdf - Add signature fields https://github.com/MatthiasValvekens/pyHanko - store pdf file (maybe seafile?) (or nextcloud)

I don't think Okular supports PKCS#11 out of the box, but if you're OK with CLI tooling, this might suit your needs: https://github.com/MatthiasValvekens/pyHanko (full disclosure: I wrote that tool, so assume I'm biased).

Shameless plug: I'm the author of this tool: https://github.com/MatthiasValvekens/pyHanko/.

Certomancer started out as a weekend-long hacking session because I wanted to put the test suite for pyHanko on more solid foundations. I more or less knew where I wanted to go: I started by crafting a configuration file describing a somewhat involved testing configuration, and then implemented features incrementally until the tool was capable of handling the sample config I initially put together. This is the result.

If you aren't afraid of some command-line tooling, you can use pyHanko: https://github.com/MatthiasValvekens/pyHanko/. It's mainly a signing tool, but the library behind it supports literally every encryption scheme in the PDF standard. The CLI is a bit more restricted, but it'll probably still do the job in this particular case.

I highly recommend Rnote to anyone on Linux that misses the "hodgepodge" notetaking of apps like OneNote. It works like a dream on touchscreens and drawing tablets, with a surprising amount of configuration under the hood.

Also worth noting is Xournal, an older but similar project: https://xournalpp.github.io/

I've been using Xournalpp[1] for many years, highlighting books as I read them, adding in text/hand drawn annotations in whitespaces if necessary. Unlike other PDF readers/annotators, it saves a separate file, so the original PDF is untouched. It can also export the annotated PDF as a new PDF with highlights and annotations.

Obsidian[2] also has PDF support, where you can open a markdown document side by side with the PDF to take notes as you read. I think it also lets you highlight the PDF itself.

Emacs I think has a similar feature, via plugins/org-mode(?) to the Obsidian setup.

And of course your typical PDF reader probably has support for highlighting PDFs too, but I find them clunky and they save by exporting a PDF, which can be a bit heavy-handed IMO compared to just saving the annotations/highlights as a separate file as Xournalpp does.

[1]: https://github.com/xournalpp/xournalpp/

Currently, I am trying to build a small open source NLP project for which I first find text on a page and then translate it; see the current project state here: https://github.com/PellelNitram/xournalpp_htr. The purpose of this project is to make handwritten text in Xournal++ searchable for all users.

[Xournal++](https://xournalpp.github.io/) is in my option the best handwritten note-taking software out there, because it has all the coolest features (like LaTeX snippets and shapes) and it's open source too, so make sure to check it out!