Earlier quoted context omitted.
It definitely is open source even if they don’t disclose all details behind the training
Interesting as the literal source of the result is not open
The model weights in eg TensorFlow are the source code.
It is not a von-Neumann architecture but a gigabyte of model weights is the executable part, no less than a gigabyte of imperative code.
Now, the training of the model is akin to the process of writing the code. In classical imperative languages that code may be such spaghetti code that each part would be intertwined with 40 others, so you can’t just modify something easily.
So the fact that you can’t modify the code is Freedom 2 or whatever. But at least you have Freedom 0 of hosting the model where You want and not getting charged for it an exorbitant amount or getting cut off, or having the model change out from under you via RLHF for political correctnesss or whatever.
OpenAI has not even met Freedom Zero of FSR or OSI’s definition. But others can.