Microsoft

Microsoft is one of the three dominant hyperscalers and OpenAI's largest investor and compute partner. Its Azure cloud hosts frontier training and inference at massive scale, its Copilot products embed AI across Microsoft 365, GitHub, and Windows, and its Microsoft AI division builds first-party models under Mustafa Suleyman. Few companies touch as much of the AI value chain, from infrastructure to consumer products.

Founded by Bill Gates and Paul Allen in 1975, Microsoft under CEO Satya Nadella reinvented itself around cloud computing and, since 2019, around AI through its OpenAI partnership. It has invested more than $13 billion in OpenAI and provides the Azure supercomputers on which many of OpenAI's models were trained.

Azure is the commercial engine: it hosts OpenAI models via Azure OpenAI Service, offers a broad model catalog, and builds custom Maia AI accelerators and Cobalt Arm CPUs to reduce dependence on merchant silicon. GitHub Copilot pioneered AI-assisted coding, and Microsoft 365 Copilot brought generative AI to enterprise productivity at scale.

In 2024 Microsoft formed Microsoft AI, hiring Mustafa Suleyman to lead consumer AI and first-party model development — a hedge that reduces sole reliance on OpenAI even as the two remain deeply intertwined following OpenAI's 2025 restructuring, in which Microsoft holds roughly a quarter of the for-profit entity.