I think you missed the "or" in the parent post. SQLite is closed for contributions, but it's still open source in the sense that anyone can take the source code, make changes and use it in their own projects. From the SQLite website:

> SQLite source code is in the public-domain and is free to everyone to use for any purpose.

That being said, I agree with your sibling poster that "open contribution" is not a requirement for "open source".