Open source means that you can build from said source.

You can e.g. give away a closed-source game engine with an editor, where you can modify the prebuilt levels, and create your own, to your heart's content. But you can't build it from scratch in a controlled environment, and can't audit it. You also can't do modifications where the level editor interface is not sufficient, e.g. in the renderer. That's not open source, that's freeware.

For ML models, the training set is a crucial part of their source.

Open source means being able to verify how the sausage is made. Getting a premade sausage and saying “oh you can still eat it and spice it up however you like” isn’t that.

I’m happy open weights exist, but it is not truly open source.

Define these terms:

- Pretrain

- Fine tune

- Catastrophic forgetting

- Learning rate

- Adapter layer

If you understand these terms, then you understand why "open weights" are not the same as "open source".

"Open weights" are obfuscated and minified freeware.