Event Monitoring Service, a Hewlett-Packard system resources monitor

Energy Management System, a system to control, monitor, and optimize the generation and flow of Electric Power

Electromagnetic spectrum

Emergency Medical Services

European MapleStory

Eastern Middle School

Emergency Medical Technician

Express Mail Service

Ems Dispatch, a historical document

Expanded memory Specification

European Monetary System, 1979

eosinophilia-myalgia syndrome

Equine Metabolic Syndrome

Ems (Eems), a river in northwestern Germany and northeastern Netherlands.

Eagleview Middle School

European Macroseismic Scale

Earthen Manure Storage

Enterprise Messaging System

Penn State College of Earth and Mineral Sciences (commonly referred to as EMS)

Extended finite state machine

European Mathematical Society

Electronics Manufacturing Services

Electronic Muscle Stimulation

Eastern Mountain Sports, an outdoor retailer

Environmental Management System

Environmental Middle School

Ethyl methanesulfonate (or methanesulfonic acid ethyl ester), a mutagen

Electronic Music Studios (London) Ltd, manufacturers of synthesisers

Ems, a British iron sailing ship

Environmental Media Services

Eastern Mennonite School

Elwood Middle School

Eastern Mennonite Seminary

Edinburgh Mathematical Society

Enhanced Messaging Service (application-level extension to Short Message Service (SMS) for mobile phone)

Eitzen Maritime Services of Oslo

The Fédération Internationale Féline, a federation of cat registries

Element management system, telecommunications

E. M. S. Namboodiripad, for many years General Secretary of the Communist Party of India and the first Chief Minister of the state of Kerala.

Engine Management System, a.k.a electronic control unit

Enterprise Message Service, JMS messaging system by Tibco Software

Electronic Meeting System (mobile worker applications enabled by Groupware)

Emergency Management Services provides serial console support for MS-Windows XP

Domat/Ems, a municipality in the district of Imboden in the Swiss canton of Grisons.

River Ems, a river with its mouth at Emsworth, Hampshire.

Bad Ems, a German spa town in Rhineland-Palatinate, until 1913 the town named Ems.

EMS Express Mail Service, an international express postal service offered by postal-administration members of the Universal Postal Union (UPU)

English Market Selection, a term used for Cigars with a certain colour of wrapper, also sometimes referred to as 'natural'

The plural of em with several meanings including "em" a unit of measure in typography