Is it though? The website does say "All of the code and documentation in SQLite has been dedicated to the public domain by the authors" but copyright law has no exception for "dedications" to the public domain. At best the authors are estopped from bringing suit but even that is unclear.
Companies can buy licences if they're uncomfortable with the Public Domain dedication:
[quote]
Licenses are available to satisfy the following needs:
* You want indemnity against claims of copyright infringement.
* You are using SQLite in a jurisdiction that does not recognize the public domain.
* You are using SQLite in a jurisdiction that does not recognize the right of authors to dedicate their work to the public domain.
* You want to hold a tangible legal document as evidence that you have the legal right to use and distribute SQLite.
* Your legal department tells you that you have to purchase a license.
They could have CC0 licensed the code or they could have said they would not enforce their copyright. They did neither. SQLite is closed source. The "dedication" (which has no legal effect, what does it even mean?) encourages widespread adoption and big players are spooked into paying for a license (or "warranty of title"). That's quite a strategy.
Is it though? The website does say "All of the code and documentation in SQLite has been dedicated to the public domain by the authors" but copyright law has no exception for "dedications" to the public domain. At best the authors are estopped from bringing suit but even that is unclear.