Cost / License
- Free
- Open Source (MIT)
Application types
Platforms
- Mac
- Windows
- Linux
- Android
- iPhone
- Android Tablet
- iPad
- Flathub




Ideon is described as 'Open-source, self-hosted alternative to tools like Heptabase and Kosmik, specifically designed for technical projects. It provides an infinite spatial canvas where users can organize information visually rather than in linear documents or folder structures' and is an app in the office & productivity category. There are more than 50 alternatives to Ideon for a variety of platforms, including Mac, Windows, Linux, Web-based and Android apps. The best Ideon alternative is Obsidian, which is free. Other great apps like Ideon are Joplin, Logseq, Anytype and Notion.




Offers limitless nested lists for outlining, instant sync on web and mobile, real-time collaboration, file and photo uploads, kanban boards, tagging, offline editing, hoisting for branch focus, content sharing, text highlighting, and Dropbox auto-backup.




Open-source wiki and documentation solution offering real-time collaborative editing, robust permissions, group management, spaces for organizing content, inline commenting, full-page history, advanced full-text search, nested pages, attachments, and flexible storage.




SiYuan is a desktop Markdown Block-Reference and Bidirectional-Link note-taking application. Support fine-grained block-level reference and Markdown WYSIWYG.




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.




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.




A note-taking tool that gives you memory superpowers. It automatically generates flashcards from your notes and figures out the optimal time to practice each flashcard.



Capacities offers a revolutionary note-taking experience by utilizing a network-based structure for knowledge capture and organization. Users create unique entities like ideas and questions in a graph view, fostering personalized and interconnected know-how beyond traditional folders.




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.

TheBrain helps you organize all your Web pages, contacts, documents, emails and files in a context-driven visual map.




Secure device-synced notepad using AES-GCM-256 encryption to protect confidential data. Features include a tree-structure for note organization, historical changes tracking, and collaboration options. Supports all major platforms with cloud sync and offline access.




Microsoft Loop is an app designed for co-creation that brings your team and ideas together in one place. With Loop components that sync across apps in real-time, you can stay in sync without switching apps and get more done right where you are.



