What you may do
- Use it and run it for any purpose, including commercially and as part of paid work.
- Read all of the source. There is no hidden core; the repository holds the product.
- Modify it, for yourself or for a client.
- Redistribute it unmodified as a dependency of something else you make.
What you may not do
- Offer it to third parties as a competing commercial product.
- Run it as a hosted service for other people.
That is the whole restriction, and it is the ordinary shape of the Business Source License: everything is permitted except turning the work into the same business it was built to be.
When it becomes Apache 2.0
Each version converts to the Apache License 2.0 four years after that version is first published.
The BSL applies per version, not to the project as a whole, so there is no single date on which everything changes. Each release carries its own conversion date, recorded in CHANGE-DATE-LEDGER.md in the repository.
A conversion date, once published for a version, cannot be moved later. That is the point of writing them down in a tracked file rather than in a licence header that could quietly change.
Packages with their own licence
Some packages ship independently and carry their own licence file. A package with its own LICENSE is governed by that licence, not by BSL. Check the package directory rather than assuming the root licence reaches it.
Contributing
LEDAR uses the Developer Certificate of Origin, not a contributor licence agreement. You keep your copyright, and your contribution can never be relicensed into a closed commercial tier.
That was decided before the first contribution arrived, because deciding it afterwards does not work. CONTRIBUTING.md explains what it rules out and why the option was given up deliberately.
Why not open source now
Because the honest answer is that the restriction exists to keep a business possible while the product is young, and pretending otherwise by calling it open source would be a misuse of a term with a specific meaning.
The conversion schedule is the counterweight: the restriction expires on a published date rather than at the author’s convenience, and it expires for every version whether or not the project is still commercially active.