GPT-J is a model released by EleutherAI shortly after its release of GPTNeo, with the aim of delveoping an open source model with capabilities similar to OpenAI's GPT-3 model. With a larger size than GPTNeo, GPT-J also performs better on various benchmarks.
Orca is a descendant of LLaMA developed by Microsoft with finetuning on explanation traces obtained from GPT-4.
Orca-13B is a LLM developed by Microsoft. It is based on LLaMA with finetuning on complex explanation traces obtained from GPT-4. By using rich signals, Orca surpasses the performance of models such as Vicuna-13B on complex tasks. However, given its model backbone and the data used for its finetuning, Orca is under noncommercial use.
Further reading