• Manned Spaceflight Engineer, an astronaut in the United States Air Force's
Manned Spaceflight Engineer Program •
Mars Surface Exploration •
Materials Science and Engineering •
Maunakea Spectroscopic Explorer, a planned renovation of the
Canada–France–Hawaii Telescope •
Maximum spacing estimation, in statistics •
Mean squared error, in statistics •
Mechanically stabilized earth •
Mental status examination, used by clinicians to assess aspects of a patient's mental state •
Mercury Surface Element, the lander portion of BepiColombo space mission •
MSE (centrifuges), Measuring and Scientific Equipment, manufacturer of laboratory centrifuges •
Selenomethionine, a naturally occurring amino acid
Computing •
Message Stream Encryption, a BitTorrent protocol encryption •
Media Source Extensions, a W3C standard for Javascript media streaming •
Metasearch engine, a search engine that consolidates results from other search engines •
Microsoft Security Essentials, a free antivirus software •
Mobile Subscriber Equipment, a tactical communications system formerly used by units such as the
17th Signal Battalion (United States) ==Stock exchanges==