GPT-2 is a transformers model pretrained on a very large corpus of English data in a self-supervised fashion. This means it was pretrained on the raw texts only, with no humans labelling them in any way (which is why it can use lots of publicly available data) with an automatic process to generate inputs and labels from those texts. More precisely, it was trained to guess the next word in sentences.
Whisper is a general-purpose speech recognition model. It is trained on a large dataset of diverse audio and is also a multitasking model that can perform multilingual speech recognition, speech translation, and language identification.
OpenAI Gym is a toolkit for developing and comparing reinforcement learning algorithms that supports teaching agents everything from walking to playing games like Pong or Go.
OpenAI is an AI research and deployment company that conducts research and implements machine learning.