My understanding is that the original Transformer paper ("Attention is All You Need") and BERT papers came from Google. In particular, BERT's pre-training task

My understanding is that the original Transformer paper ("Attention is All You Need") and BERT papers came from Google. In particular, BERT's pre-training task is to predict how to fill-in-the-blank from a sentence that's missing a random word. OpenAI started from that architecture and made it output text generatively, by using beam search on top of a next-token prediction task.