Turtl - The secure, collaborative notebook
DokuWiki - DokuWiki is a simple to use and highly versatile Open Source wiki software that doesn't require a database.
Tomboy - Apps/Tomboy - GNOME Wiki!
Wiki.js - An open source, modern and powerful wiki app built on Node.js, Git, and Markdown.
Carnet - Opensource rich text note taking app
TiddlyWiki - a non-linear personal web notebook