OpenAI

[San Francisco, California, USA][founded 2015][backed by Microsoft (27%), OpenAI Foundation (26%); OpenAI Group PBC]openai.com

Founded in December 2015 and headquartered in San Francisco, OpenAI restructured in October 2025 into OpenAI Group PBC, a public benefit corporation controlled by the nonprofit OpenAI Foundation, with Microsoft holding about 27 percent. The lab develops frontier language, reasoning and multimodal models with the stated mission of ensuring AGI benefits humanity. It ships the GPT family, the o-series reasoning models (now being retired), the GPT Image models, text-to-speech, and the Sora video models, which OpenAI announced it would shut down in March 2026.