How is this legal?

In a world where Meta got caught torrenting entire book archives, anything goes these days.

But strictly speaking, it’s not because it’s based on decompilation and not a clean room reimplementation of the engine. That’s like using a translation service to translate a copyrighted book into another language and then manually iron out the kinks. But in a world of mass piracy for LLM training, nobody gives a shit about such little projects any longer.