Just finished with 1.0 Notes of the Networks. It is a binder of notes that is targeted towards learners or re-learners of the Basics of the Computer Networks.
GitHub Repo: https://github.com/EvgeniGenchev/The_Notes_Of_Networks
Open-source / Open alternatives I use in my workflow:
MS Office -> LibreOffice
Gmail -> Tutanota
Google Search engine -> Startpage
Google Chrome -> Firefox
Google Translate -> DeepL
Google Maps -> OsmAnd
What's app -> Signal
Visual Code -> Doom Emacs
Django Dev
Open Software... This is the way