FlatPad is a small tool that makes living with other people easier. See who is currently at home and share text on a digital pad.

The Markdown-based note-taking app that doesn't suck.

BookStack is a simple, self-hosted, easy-to-use platform for organising and storing information.

Trilium Notes is a hierarchical note taking application with focus on building large personal knowledge bases.

A hierarchical note taking application, featuring rich text and syntax highlighting, storing data in a single xml or sqlite file.

This is an open source clone of notepad.cc, which is now defunct.