Open source alternatives to Craft

By GitHub stars it is AppFlowy, with 78,875 stars and a commit on 2 Nov. Choose AppFlowy when you want to host it yourself and keep your data on your own server. Next come La Suite Docs (16,989 stars) and Notesnook (14,934 stars).

Yes. The code of all 5 is public under AGPL 3.0, MIT, GPL 3.0 or MPL 2.0, so you can use them with no licence fee. Running one yourself costs the server and your time to look after it, and some makers also sell a hosted plan.

Start from the job you use Craft for. Choose Notesnook when you want to host it yourself and keep your data on your own server. Choose La Suite Docs when you want block-based documents with live co-editing on servers you run, with no per-member subscription.

All 5: AppFlowy, La Suite Docs, Notesnook, Darkwrite and Koru. Each tool's page says what it needs to run.

4 of the 5 we track had a commit in the last 30 days, among them AppFlowy, La Suite Docs, Notesnook and Koru. The quietest is Darkwrite, last changed on 15 Oct. A recent commit shows the project is kept up, not that it will stay that way.

AGPL 3.0 (2), MIT (1), GPL 3.0 (1), MPL 2.0 (1). MIT, BSD and Apache let you change and reuse the code freely. GPL and AGPL ask you to share your changes under the same licence when you give the software to others, and AGPL also counts letting people use it over a network.

The hosting. Craft's maker runs the servers for you; with an open source tool the updates, backups, security fixes and support are yours, unless you take the maker's hosted plan. Features differ too, so check what each one imports and exports before you move your data.