Boostnote - Boostnote is an open-source note-taking app.
Jupyter - Project Jupyter exists to develop open-source software, open-standards, and services for interactive computing across dozens of programming languages. Ready to get started? Try it in your browser Install the Notebook.
Supernotes - The fastest way to take notes and collaborate with friends. Create notecards with Markdown, LaTeX, images, emojis and more. Get started for free!
Kajero - Interactive JavaScript notebooks - create good-looking, responsive, interactive documents.
Draft - A tool for developers to create cloud-native applications on Kubernetes
Calculist - The open-source, web-based thinking tool that facilitates effective thinking for solving problems.