Microsoft
Microsoft develops the Phi checkpoint family and the MAI model line. MAI access varies by release: Foundry previews, Copilot integration, local model packages and restricted security products have different terms.
Company & leadership
- Chairman and CEO
- Satya Nadella
- Public listing began
- 1986.
Founders
- Bill Gates and Paul Allen
From PC software to cloud and AI
Bill Gates and Paul Allen started Microsoft to write software for the Altair 8800. The company first operated in Albuquerque. It moved to Bellevue in 1979 and to its Redmond campus in 1986. Windows first shipped in 1985.
Microsoft incorporated in 1981 and went public on 13 March 1986. Its product history includes Office, Windows, Xbox and Azure. Satya Nadella became CEO in February 2014. The company now develops its own Phi models as well as operating services that host models from other developers.
Choose by task and architecture
Practical guidance. Separate three decisions: the task, the input format and the machine that will serve it. A small model with a long context may fit a document workflow better than a larger model with a shorter limit. A visual grounding model needs a coordinate contract, while an ordinary text assistant needs a response contract.
Check the exact checkpoint before deployment
Practical guidance. The Phi name does not imply one architecture or one prompt format. Record the repository, revision, precision and tokenizer used by your deployment. Keep those choices fixed while reviewing changes. Hosting another developer's model in Microsoft Foundry does not make Microsoft its original developer.
What this catalog covers
Practical guidance. This selection covers current reviewed MAI releases, the Phi-4 instruction and reasoning line, SlimMoE variants and Phi Ground Any. It omits older MAI versions, Phi-1 through Phi-3, every precision conversion and third-party models hosted in Azure. A published weight package, hosted API and product integration have separate access conditions.