> Perhaps that's what we should be using: copyleft vs open source, instead of free software vs open source.

Unless I misunderstand them, what about using the actual definitions?

- Proprietary software can be closed-source or source-available

- Open-source software can be under a permissive or copyleft license

- Free software is a philosophy around open-source software, but in practice FOSS and OSS are mostly the same thing.

These are good definitions but the original post wasn't referring to people not taking into account the philosophical part of free software, unless it really meant "copyleft".

A permissive licence doesn't really transmit the intent of the author, philosophy or not (it doesn't really matter, the licence is the same).

A copyleft licence, on the other hand, backs the philosophy behind free software via the actual licence.

But you are right, it should be "copyleft vs permissive open source".

[delayed]