[djvdorp]

There apparently also is paperless-ng: https://github.com/jonaswinkler/paperless-ng

And this slightly older FileBasedMiniDMS: https://github.com/stweiss/FileBasedMiniDMS

I tried both Mayan and Paperless (regular) myself to replace my Evernote Premium setup, they haven't convinced me yet.

I am currently trying out https://github.com/jbarlow83/OCRmyPDF myself (had to fork it to add my own language to the Dockerfile) and then will either let my NAS index it afterwards or Dropbox/Nextcloud maybe. Apparently locally they get indexed very well with either Gnome (Linux) or Finder (Mac) or Explorer (Windows).