OpenAI

OpenAI develops AI models and applications for consumers, developers, and organizations. ChatGPT supports conversational assistance, while ChatGPT Work carries out tasks across connected apps and files, producing spreadsheets, presentations, documents, and web apps. Users can review progress, steer work, and approve important actions. Codex helps developers build software and review pull requests; OpenAI’s APIs let developers build on its models. Together, these products span direct assistance, software development, and workflows involving multiple tools.

Founded as a nonprofit in 2015, OpenAI began with Sam Altman and Elon Musk as co-chairs, Greg Brockman as CTO, and Ilya Sutskever as research director. Altman is its current CEO. Its InstructGPT research applied reinforcement learning from human feedback to improve instruction following: human demonstrations and ranked model responses supplied training data, and a learned reward model guided further training. This approach addressed the gap between predicting text and responding to user intentions.

Following its completed 2025 recapitalization, the nonprofit OpenAI Foundation continues to control OpenAI Group PBC, its commercial public benefit corporation. In March 2026, OpenAI reported more than 900 million weekly active ChatGPT users and over 50 million subscribers. That month, it closed a funding round with $122 billion in committed capital at an $852 billion post-money valuation. By July 2026, the company reported more than 5 million weekly Codex users, including more than 1 million using it outside software development.