Anytype

AppFlowy

AppFlowy is an open-source note-taking and database app that allows users to create custom databases and tables to organize their data. It provides a flexible and customizable way to manage information, with features such as table views, Kanban boards, and calendar views.

Standard Notes

Standard Notes is a privacy-first note-taking app that encrypts every note and file with audited, industry-standard end-to-end encryption before it ever leaves the device. Only the account holder holds the keys needed to decrypt their data, and the company positions itself directly against services like Evernote, Google Keep, and Notion on the grounds that those services cannot fully protect user data from employer or government access. The app syncs notes and files across unlimited devices on Windows, Mac, Linux, iOS, Android, and the web, and it keeps an offline copy of everything so notes remain accessible without an internet connection. Beyond plain notes, it supports markdown, rich text, task lists, code snippets, and spreadsheets through an extensible editor system, and its source code is open and independently security-audited. The company states it takes no venture capital and earns 100 percent of its revenue from paying subscribers.

Obsidian

Obsidian is a note-taking and personal knowledge management app built around plain markdown files stored locally on your device. Rather than a rigid folder hierarchy, Obsidian encourages a networked structure through bidirectional links, backlinks, and an interactive graph view that visualizes how notes connect. Because notes are just markdown files on disk, Obsidian is fast, works fully offline, and keeps your data portable - there is no proprietary lock-in. A large community plugin ecosystem extends the core app with everything from spaced-repetition flashcards to kanban boards and calendar views. Obsidian Sync and Obsidian Publish are optional paid add-ons for cross-device syncing and publishing notes as a website, but the core app is free for personal use.

Foam

Foam is a free, open-source note-taking application that uses a graph database to store notes as a network of interconnected ideas. It's designed to help users create a knowledge graph, where each note is a node that can be linked to other notes, creating a web of relationships between ideas.