Free to self-host, including commercially and in production.
Licence
What you may do with hoardDB, in plain language. The licence itself is quoted below, unedited.
You may self-host it, including commercially
Run it for your own applications, your customers' applications and your internal systems, at any scale, without paying anyone.
The one thing it does not grant
The one thing the licence does not grant is offering hoardDB itself as a database service to third parties. For that, talk to Boeger IT Sh.p.K, Tirana, Albania.
If your product is a managed hoardDB that third parties connect to and store their data in, that needs a commercial licence.
It is source-available, not open source
The Business Source License is not an Open Source licence, and it says so itself. The Licensed Work converts to the Apache License 2.0 on the Change Date, or on the fourth anniversary of a version's first public distribution, whichever comes first.
Source-available is not the same as open source. Developers check this, so the site states it rather than leaving it to be discovered.
Client libraries carry no usage restriction
Client libraries live under clients/ and are Apache-2.0, so a driver you link into your own program carries no usage restriction.
This is a statement about the licence of a directory. clients/ holds a LICENSE and nothing else today; no client library has shipped.
The licence, verbatim
Read from LICENSE in the repository at build time.
The client libraries' licence, verbatim
Read from clients/LICENSE in the repository at build time.