Microsoft uses this as an abbreviation for projects such as ch9.ms, 1drv.ms for OneDrive, and for Defender for Cloud Apps. In particular, aka.ms is used extensively as a URL shortener for Microsoft's web sites, such as http://aka.ms/MFAsetup.
Websites based in, or having to do with, the U.S. state of Mississippi also use the .ms domain as MS is the code and official United States Postal Service abbreviation for the state. Technically, Mississippi is assigned .ms.us under the .us locality namespace.
Some companies based in the Brazilian state of Mato Grosso do Sul () use the .ms TLD
The New York Times uses .ms as a top level domain name for permalinks referring to New York Times addresses. For example, reaches The New York Times homepage.