What are ‘open’ AI models?

The tech industry faced something of a reckoning in late 2022 with the arrival of OpenAI’s ChatGPT , a simple chatbot that could answer questions, seemingly by magic. The early frontier large language models (LLMs) from OpenAI and rivals like Anthropic and Google could reason, solve problems, and answer detailed queries put to them using natural language. But no one knew exactly what was in the LLM black boxes underpinning the services.