The best open source alternative to Microsoft OneNote is Zim. If that doesn't suit you, our users have ranked more than 100 alternatives to Microsoft OneNote and loads of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Microsoft OneNote are Joplin, Logseq, Xournal++ and Standard Notes.
SiYuan is a desktop Markdown Block-Reference and Bidirectional-Link note-taking application. Support fine-grained block-level reference and Markdown WYSIWYG.
Markor is a TextEditor for Android, versatile, flexible, and lightweight. Markor utilizes simple markup formats like Markdown and todo.txt for note-taking and list management. It is versatile at working with text; it can also be used for keeping bookmarks, copying to clipboard...
Open-source, feature-filled and uses open formats so it is future-proof. Actively updated with new features. A great app for notes, to-do lists and jotting down thoughts and ideas.
Plain text notepad with markdown support and todo list manager for Linux, Mac OS X and Windows, that works together with the notes application of ownCloud.
Open-source note-taking tool offering AI-enhanced retrieval with RAG technology, secure self-hosted data storage, Markdown support, and transparent community collaboration on GitHub for efficient, private, and effortless note management.
Protects your private notes with a password. Notebook PEA is a self-decrypting archive, that will never store unencrypted text on your disk.
Collaborative platform for real-time note-taking, documentation, and wikis, featuring offline editing, granular permissions, AI-assisted writing, multiple export formats, user-friendly formatting, scalable team support, customizable templates, and open-source licensing.
Lightweight, self-hosted app for managing personal checklists and notes with drag and drop, progress bars, Kanban boards, Markdown WYSIWYG editor, file-based data, user management, sharing options, themes, open source, and API access.
Reor is an AI-powered desktop note-taking app: it automatically links related ideas, answers questions on your notes and provides semantic search. Everything is stored locally and you can edit your notes with an Obsidian-like markdown editor.
OpenBoard is a cross-platform (Linux / Windows / macOS) interactive whiteboard application. It is currently maintained by the Education Department (DIP) of the Canton of Geneva in Switzerland.
The most important feature in OneNote, for me, is the "free-hand" writing feature on any PDF file. OpenBoard allows you to do so. It is also set up to take the whole screen with little distraction on it, so you can work and explain things to your students and collaborators.
Rnote aims to be a simple but functional note taking application for freehand drawing or annotating pictures or documents. It eventually should be able to import / export various media file formats.
It's insanely fast (and written in Rust). Pen support. Pages and Folder support. Open-Source. Saves everything as file and thus can be used in a cloud sync. Has basic Textediting functionality (but not very good for structured Texts, more made for freeform drawing and handwritten notes). PDF insertion (no real annotation though)!
Provides end-to-end encrypted note-taking, file storage, and sketching with syncing across platforms, zero data collection, no personal info or passwords required, open-source code for transparency, and optional premium storage, all via native and CLI tools.
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Markor is light, fast and uses Markdown text so your notes can be read on all devices. With OneNote you need the app to open your notes.