Open-source Capacities alternatives

AppFlowy is an open-source workspace that brings documents, wikis, project and task management and team collaboration into one app. It is presented as an alternative to Notion, and its topics also tag it as a Confluence alternative, with the emphasis on keeping control of your own data.

The client is built with Flutter and a Rust core, giving apps for macOS, Windows and Linux plus iOS and Android versions. Desktop builds can be downloaded directly or from channels such as Flathub and Snapcraft. AI features are part of the workspace, and a public roadmap and active forum let users propose features. Translations are contributed through JSON files and tools such as inlang.

The project is AGPL-3.0 licensed and has documentation for self-hosting the server side, so organizations can keep content on their own infrastructure. A hosted version is available through appflowy.com for people who do not want to run servers. It suits teams looking for a Notion-style workspace with a privacy-first stance.

AFFiNE is an open-source workspace that combines writing, drawing and planning in a single app. Documents, an edgeless whiteboard and table views share the same blocks, so you can place rich text, sticky notes, embedded web pages, database views, linked pages, shapes and even slides anywhere on one canvas. It is presented as an alternative to Notion and Miro.

The project stresses local-first storage, meaning your data lives on your own device first, together with real-time collaboration. A multimodal AI assistant helps write reports, turn outlines into slides, summarize articles into mind maps and organize tasks. Under the hood it uses CRDTs for syncing and is built mostly in TypeScript and Rust, with Electron for the desktop app. It also supports Markdown, wiki and knowledge-base use, and presentations.

AFFiNE's license is listed as 'Other' on GitHub, so review it before commercial use. There is a live demo and documentation on the project site, a hosted version is available, and the app can also be self-hosted.

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.

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.

Tangent is a local note writing and personal knowledge management tool, heavily inspired by Obsidian but developed in its own direction. It uses [[Wiki Links]] and a slightly customized Markdown syntax, and notes are styled as you write, with Markdown syntax hidden and revealed as needed.

Other key features include a two-dimensional connected map of your navigation and linking history, a sliding panel interface inspired by Andy Matuschak's notes, a writing focus mode that highlights the current paragraph, line or sentence, note views that show collections as cards or an infinite feed, and a custom query language with autocomplete for complex searches. Notes can embed images, link previews, PDFs, audio and video, including YouTube links. Pre-built binaries are available from the downloads page and Flathub.

This monorepo holds the Electron-based Tangent application, the source of tangentnotes.com, a test workspace generator, an HTML-to-Markdown parser and the query language parser. Tangent is written in TypeScript and licensed under Apache-2.0.

Notabase is a personal knowledge base built for networked thinking. Notes link to one another, so you can move through them like web pages and notice connections you would not have found by filing them in folders. The README describes it as a personal Wikipedia you can edit and browse, and says it draws inspiration from Notion, Obsidian, Typora and Roam Research.

The editor is WYSIWYG with Markdown support. Linked and unlinked references show which other notes mention the one you are viewing, and block references embed a passage from another note that updates when the original changes. Notes can be organized with links, tags and nesting, browsed with page stacking, explored in a graph view and found through full-text search. It installs as a progressive web app for faster loading and offline viewing, and notes sync to the cloud across devices.

You can import or export your notes at any time. Notabase is written in TypeScript and licensed under AGPL-3.0. The project is focused on its hosted experience, but the README says self-hosting or running it locally is possible. It is funded by sponsors and developed in the open.