Open-source Obsidian alternatives

SiYuan is an open-source, privacy-first personal knowledge management system. Its distinctive feature is fine-grained, block-level referencing: any block can be linked to or embedded elsewhere, with two-way links, custom attributes and SQL query embeds. Editing is Markdown WYSIWYG, and the project describes itself as a workspace where humans and AI agents work together. It is local-first and self-hostable.

The editor supports block-style writing, list outlines, block zoom-in, very large documents, math formulas, charts, flowcharts and Gantt charts. Web clipping, PDF annotation links, flashcards with spaced repetition, a database table view, Tesseract OCR and multi-tab split-screen layouts are included. You can export blocks and embeds, standard Markdown with assets, or PDF, Word and HTML. AI writing and Q and A chat can use the OpenAI API, and template and JavaScript or CSS snippets allow customization.

SiYuan is AGPL-3.0 licensed and available as desktop apps, mobile apps for Android, iOS and HarmonyOS, an installation package, a package manager, and Docker, Kubernetes, Unraid and TrueNAS hosting. A command line interface and an app market for extensions exist. Most features are free, even for commercial use.

Logseq is an open-source platform for knowledge management and collaboration that puts privacy and local storage first. Notes are organized as linked blocks in an outliner, forming a knowledge graph, and topics show it works with both Markdown and Org-mode files and can be backed by Git.

The project is moving toward a database-backed version that introduces DB graphs. That version is in beta, comes with a new iOS mobile app in alpha and a Real Time Collaboration approach to syncing graphs across devices or working with others, also in alpha. Because data loss is possible while these features mature, the maintainers recommend automated backups. A plugin API, themes and a public roadmap round out the ecosystem.

Logseq is written in Clojure and ClojureScript under the AGPL-3.0 license, and desktop builds are available from the releases page. It appeals to researchers, students and knowledge workers who want a personal wiki with bidirectional links and full ownership of their files.

Trilium Notes is a free, open-source, cross-platform note-taking application focused on building large personal knowledge bases. Notes are arranged in a tree of arbitrary depth, and a single note can be cloned into several places in the tree, which lets you organize the same material along different lines without duplicating it.

The editor is a rich WYSIWYG one with tables, images, math and Markdown autoformatting, and there is also support for source code notes with syntax highlighting. Navigation relies on fast jumps between notes, full-text search and note hoisting. Notes are versioned automatically, and attributes can be used to organize, query and script notes. The interface is available in several languages, and built-in documentation opens with F1.

The project, now maintained as TriliumNext, is AGPL-3.0 licensed and built with TypeScript and Electron. It provides desktop builds as well as a server setup with Docker, so you can keep your notes on your own hardware. Stable releases are recommended, with nightly builds available for those who want the newest changes.

Foam is a personal knowledge management system that lives inside Visual Studio Code and GitHub. It is intended for organizing research, keeping notes you can rediscover, writing long-form content and, if you want, publishing it to the web. The notes are plain Markdown files you own, so you can share and collaborate on them with anyone.

Its features center on linking notes together. A graph visualization shows how notes connect, link autocompletion helps create connections and placeholders, and links are updated automatically when a file is renamed. Foam supports files with the same name in different folders by using the shortest identifier needed, and it helps find and fix ambiguous wikilinks. Link preview, go to definition and peek references let you see where a note is mentioned. Topics include Zettelkasten and PKM workflows.

Foam is a free, open-source VS Code extension written in TypeScript, and its license is listed as 'Other' on GitHub. It requires VS Code, so it suits developers and technical writers already comfortable in that editor who want a notes workflow built on files and Git instead of a separate app.

Zettlr is a desktop Markdown editor aimed at academic and long-form writing. It presents itself as a publication workbench, combining note-taking, drafting, reference management and export in one application, with a focus on keeping your notes private and stored as ordinary files on your own computer.

Citations integrate with reference managers such as Zotero and JabRef, and exports rely on Pandoc, LaTeX and Textbundle, with support for LaTeX and Word templates. Other capabilities include snippets for boilerplate text, themes with dark modes and custom CSS, code highlighting, full-text search, and techniques from the Zettelkasten knowledge management method. The interface is translated into over a dozen languages.

Zettlr is built with TypeScript, Electron and Node.js and released under GPL-3.0. Installers are provided for macOS, Windows and most Linux distributions, and the repository documents building from source, command-line switches and contribution workflows. The project is also reachable through a community forum, Discord and Mastodon.

VNote is a free, open-source note-taking application built with Qt and written in native C++. It currently focuses on Markdown, and aims to offer a pleasant editing experience while also providing notes management, so it is more than a simple Markdown editor.

Because it uses Qt, the same application runs on Linux, Windows and macOS. The project topics reference Vim-style editing, UML diagrams and MathJax math rendering, and the maintainers say that formats beyond Markdown are planned. Continuous builds from the master branch and stable releases are published on GitHub and Gitee.

VNote is licensed under LGPL-3.0, with bundled third-party icon sets recorded in a separate notices file. It is a desktop application that runs locally rather than a hosted service. It suits people who want local Markdown notes organized in notebooks, and developers who prefer a native editor over an Electron-based one.

NoteGen is a local-first Markdown note-taking app built around the idea of capturing first and organizing later. It helps collect scattered snippets, records and clippings and then uses AI to arrange them into clear notes, acting as a personal knowledge base.

It is a desktop application built with Tauri and Next.js. The project topics point to Markdown editing, WebDAV sync, retrieval augmented generation, MCP and agent features, and the README describes configurable model settings with an OpenAI-compatible interface for conversations, note organization, writing assistance, translation and summarization. Knowledge base features reference embeddings, reranking, OCR and speech.

NoteGen is licensed under GPL-3.0, and downloads, documentation, a business offering and community discussions are linked from the repository. Since it is a local app, you keep notes on your own machine and choose which model provider to connect, which suits people building a personal knowledge management system.

Anytype Desktop is the official desktop client for Anytype, a personal knowledge base for macOS, Windows and Linux. It lets you collect pages, tasks, wikis and journals and link them together, while keeping data stored locally and encrypted across your devices.

The client is built around composable blocks such as text, databases, kanban boards and calendars, and you can define your own Types to shape the data model. Storage is offline-first with optional peer-to-peer sync, and encryption relies on the any-sync protocol. It is an Electron application written in TypeScript, and it can be extended through a gRPC API and AI agents described in the repository.

Sign-in uses an Any-ID, and installers are published on the releases page and the download site. The code is published under the Any Source Available License 1.0 rather than a standard open-source licence, and the README includes instructions for building from source and updating the middleware.

SilverBullet is a personal knowledge base that runs in the browser and is hosted on your own server. Your content is stored as Markdown pages grouped into a Space, which you can open from a page picker as in a classic notes app, or reach through two-way wiki-style links. The project describes itself with a tongue-in-cheek phrase as a notes app on steroids.

What sets it apart is that notes can be programmed. A live-preview editor is paired with an integrated database and query syntax, and a Lua scripting environment called Space Lua lets you extend the system, build custom views and automate tasks. Repository topics highlight knowledge management, personal knowledge management, note taking and end-user programming.

SilverBullet is written in TypeScript and licensed under MIT. Because it is designed for self-hosting and plain Markdown files, it suits individuals and small teams who want a private, hackable wiki and are comfortable with a little scripting. There is no hosted service from the project.

nb is a note-taking, bookmarking, archiving, and knowledge-base tool that runs in the terminal and through a locally served web interface. It keeps everything as plain text, mainly Markdown, Org, LaTeX, and AsciiDoc files, so notes stay readable and portable without a proprietary database. It is delivered as one portable shell script under the AGPL-3.0 license.

Notes can be tagged, pinned, filtered, searched, and cross-linked with wiki-style links, and todos with tasks are supported. Every change is recorded in Git in the background, which gives versioning and syncing between machines. Bookmarks are downloaded, cleaned up, and saved as Markdown documents with full-text search over the cached page content, and notes can be password-protected with encryption.

Pandoc handles conversion to and from many document formats, and plugins and color themes allow customization. nb works on Linux and Unix systems, including macOS and Windows through WSL, MSYS, or Cygwin, and you can edit notes in whichever editor you prefer, such as Vim, Emacs, or VS Code. It suits developers and command-line users who want a private, scriptable notebook.