[sebzim4500]

I've heard that text-davinci-003 is better than ChatGPT at most tasks. They're probably using that.

[pmarreck]

is there a competing open-source version of this model I could run locally?

[liviucoman10]

I don't believe there's one just _yet_.

A quick google search reveals GPT-Neo and GPT-J as being open source. But haven't yet tried them, so can't vouch if they're as good.