The best free alternative to DEVONthink is Obsidian. If that doesn't suit you, our users have ranked more than 100 alternatives to DEVONthink and loads of them is free so hopefully you can find a suitable replacement. Other interesting free alternatives to DEVONthink are Joplin, Evernote, Notesnook and Zim.
Privacy-oriented note-taking app for non-linear thinking, blending knowledge graph creation with wiki-style linking. Supports Markdown, end-to-end encryption, and plugins for customization. Offers distraction-free mode, tags, themes, syntax highlighting, and operates offline without tracking.
Open source app for managing notes and to-dos with Markdown support. Syncs seamlessly across devices using services like Dropbox and OneDrive. Offers end-to-end encrypted synchronicity, offline access, rich import/export options, and a Web Clipper for browsers.
App designed for cross-platform note-taking and organizing. Create notes with text, images, and audio, tag and search them. Features offline access, business card scanning, and presentation modes. Integrate with LinkedIn and secure with a passcode lock.
Offers open-source, end-to-end encrypted notes with device-based privacy, cross-platform support, private vault, secure sync, offline access, markdown editor, exports to multiple formats, automatic backups, organizational tools, and strong encryption.
Zim brings the concept of a wiki to your desktop. Store information, link pages and edit with WYSISYG markup or directly typing some lightweight markup syntax and see it previewed as-you-type. Creating a new page is easy by either clicking on the "Create new note"...
The original trilium is transfered to this repo by its owner and the app continues to develop here as stated here: https://github.com/TriliumNext/Trilium
SiYuan is a desktop Markdown Block-Reference and Bidirectional-Link note-taking application. Support fine-grained block-level reference and Markdown WYSIWYG.
Qiqqa is a free research and reference manager. Search for, read and annotate your PDFs. Then review your work, write up and create bibliographies instantly.
Dendron is an open-source, local-first, markdown-based, note-taking tool built on top of VSCode. It supports all the usual features you would expect like tagging, backlinks, a graph view, split panes, and so forth.
Flexible note-taking and writing tool featuring advanced markdown with in-line images, cross-note links, live preview, hashtags, Focus Mode, plain text storage, iCloud sync, one-tap formatting, smart data recognition, and multiple export formats for portability.
RedNotebook is a graphical diary and journal helping you keep track of notes and thoughts. It includes a calendar navigation, customizable templates, export functionality and word clouds. You can also format, tag and search your entries.
Bibliography reference manager. The native file format used by JabRef is BibTeX, the standard LaTeX bibliography format.
Canada
France
EU
Italy
Pakistan
Netherlands
China
United Kingdom
Germany
Devonthink does a superb job of making many types of content searchable, and supports very flexible means of categorisation.
In particular, it doesn't lock you into "its" way of doing things.