Notion mixes three jobs: docs, a wiki and lightweight databases. No single open-source project copies all of it, so the right pick depends on which job matters most to you. Below are the projects with the biggest communities, grouped by that job.
All-in-one workspaces
1
AppFlowy AppFlowy-IO/AppFlowy
The closest to Notion’s feel: pages, databases and boards in one app, with AI features. Desktop and mobile apps plus a self-hosted server. AGPL-3.0, so changes you distribute must stay open.
2
AFFiNE toeverything/AFFiNE
Docs and an infinite whiteboard in the same space, positioned as an alternative to both Notion and Miro. Good if your team thinks visually.
3
anytype-ts anyproto/anytype-ts
Local-first and end-to-end encrypted: your data lives on your devices and syncs peer-to-peer. The repo is the desktop client; check its license file before building on it.
4
platform hcengineering/platform
Huly bundles docs with project tracking, chat and a CRM, and names Notion, Linear, Jira and Slack as what it replaces. Pick it if you want one tool instead of four.
Team wikis and documentation
5
outline outline/outline
A fast, real-time team knowledge base with a clean editor. The usual choice for teams that mainly used Notion as a wiki.
6
docmost docmost/docmost
A collaborative wiki that describes itself as an open-source alternative to Confluence and Notion. Younger than Outline but growing quickly.
7
BookStack BookStackApp/BookStack
Organises docs as shelves, books and chapters. MIT-licensed and simple to run; note that development has moved to Codeberg.
Personal knowledge and notes
8
siyuan siyuan-note/siyuan
A privacy-first, self-hosted knowledge workspace with block-level references. Strong for personal research notes.
9
logseq logseq/logseq
Outliner-style notes with backlinks, built for networked thinking rather than team databases.
10
focalboard mattermost-community/focalboard
Boards and tables that replace Notion databases used for task tracking. Now maintained by the community, so check recent activity before you commit.
How to choose
If you want the Notion experience, start with AppFlowy or AFFiNE. If you mostly need a company wiki, Outline or Docmost will feel simpler. If you care most about owning your data on your own devices, look at Anytype, SiYuan or Logseq. Whatever you pick, check the license column: AGPL is fine for internal use, but matters if you plan to sell a modified version.
How we pick: we start from every public GitHub repository with 1,000+ stars, keep the projects that do the job in the title, and read their descriptions and licenses. Stars show community size, not quality, so we also show maintenance status. Nobody paid to be listed.