Emergency medical services; public system providing urgent prehospital care and transport.

Express Mail Service; international express postal delivery network.

Electronics manufacturing services; outsourced design, assembly, and testing for electronics brands.

Environmental management system; organizational processes to monitor and improve environmental impact.

Expanded Memory Specification; DOS-era standard for accessing extra memory.

Uppercase form of ems; plural of em, a typesetting unit equal to the point size.

Plural of EM; the name of the Latin letter M.