[benesch]

Those updates are not retroactive. They apply on a go forward basis. Each day's changes become Apache 2.0 licensed on that day four years in the future.

For example, v0.28 was released on October 18, 2022, and becomes Apache 2.0 licensed four years after that date (i.e., 2.5 years from today), on October 18, 2026.

[0]: https://github.com/MaterializeInc/materialize/blob/76cb6647d...

[BeefySwain]

I love this concept. Did you all come up with this or is there prior art? Is there a name for this concept?

[benesch]

We did not originate the Business Source License (BSL/BUSL). It was originally developed by the folks behind MariaDB. Wikipedia has a good article that covers the history: https://en.wikipedia.org/wiki/Business_Source_License

Other large projects using the BSL include CockroachDB and (somewhat infamously) Terraform.

We're very glad to have been using the BSL for Materialize since our very first release. Relicensing an existing open source project under the BSL can be a painful transition.

[BeefySwain]

I was actually asking about the automatic timed re-license to Apache :)

[benesch]

Ah, I misunderstood! Yes, we may have invented that. I whipped up the cron job a few years back in response to concerns from our legal team. I’m not aware of any prior art for automatically advancing the change date for the BSL.