The Business Source License (BUSL) is source-available today and converts to an open-source license (chosen by the licensor, typically Apache-2.0 or GPL) on a pre-declared “Change Date”, typically four years after release. Until that date, commercial use outside a declared “Additional Use Grant” is restricted.
It is popular with venture-backed infrastructure companies that want to ship source code without giving competitors a free path to offer the software as a managed service.
BUSL is not OSI-approved — it is fair-code. After the conversion date, individual versions become open source.
How to apply
BUSL requires a per-project Additional Use Grant and Change Date. See the official parameters form on mariadb.com/bsl11 for the exact template. Each source file should carry:
// Change Date: 2030-01-01
// Change License: Apache-2.0
// Additional Use Grant: None
// SPDX-License-Identifier: BUSL-1.1
Full license text
Business Source License 1.1
License text copyright (c) 2020 MariaDB Corporation Ab, All Rights Reserved.
"Business Source License" is a trademark of MariaDB Corporation Ab.
Parameters
Licensor: [Your Name]
Licensed Work: [Software Name]
The Licensed Work is (c) [Year] [Licensor].
Additional Use Grant: [Describe additional permitted uses; write "None" if
there are no additional grants.]
Change Date: [Four years from release, e.g. 2030-01-01]
Change License: [e.g. Apache License, Version 2.0]
For information about alternative licensing arrangements for the Software,
please contact [contact details].
Notice
Business Source License 1.1
Terms
The Licensor hereby grants you the right to copy, modify, create derivative
works, redistribute, and make non-production use of the Licensed Work. The
Licensor may make an Additional Use Grant, above, permitting limited
production use.
Effective on the Change Date, or the fourth anniversary of the first publicly
available distribution of a specific version of the Licensed Work under this
License, whichever comes first, the Licensor hereby grants you rights under
the terms of the Change License, and the rights granted in the paragraph
above terminate.
… this text is abbreviated.
For the complete license text, see https://mariadb.com/bsl11/
Raw text also available at /license-texts/BUSL-1.1.txt — handy for curl.