fast.ai is an AI R&D lab that aims to make neural nets uncool again by offering courses, software, and books to help individuals learn and apply deep learning and AI technologies. They provide practical deep learning courses for coders, software tools like fastai for PyTorch and nbdev, and a book called Practical Deep Learning for Coders with fastai and PyTorch. Their team focuses on creating end-user products based on foundational AI research breakthroughs, and they cover a wide range of topics including AI in society, machine learning, technical aspects, education, and health.