Ladybird going source-available is quite unfortunate, seems like Gecko is the only production-ready independent browser engine we're left with.

They may, at this point, go ahead and remove "get involved" block from their website https://ladybird.org/, since it's not possible to contribute anymore.

That's not source-available, that's still open-source. Quoting Wikipedia:

> Source-available software is software released through a source code distribution model that includes arrangements where the source can be viewed, and in some cases modified, but without necessarily meeting the criteria to be called open-source.

https://en.wikipedia.org/wiki/Source-available_software

> Open-source software (OSS) is computer software that is released under a license in which the copyright holder grants users the rights to use, study, change, and distribute the software and its source code to anyone and for any purpose. Open-source software may be developed in a collaborative, public manner.

https://en.wikipedia.org/wiki/Open-source_software

And as said here, SQLite was operating like this forever.

It's not source available, source available implies some restrictions on what you can do with the source, or with any resulting binaries. This isn't a rugpull; all they're doing is closing off contributions, which has nothing to do with the license of the code.

This is not the same as source available - you can fork it, the license didn't change.