SDI

• SDI (arcade game), 1987, by Sega • S.D.I. (video game), 1986, by Cinemaware == Companies and organizations ==

• Samsung SDI, battery manufacturer • Scottish Development International • Scuba Diving International • SDI Media Group, providing subtitling and language services • SDI Presence, US IT consultancy • SDI Technologies, a consumer electronics manufacturer, New Jersey, U.S.A. • Service Desk Institute, for computer help desk staff • Slum Dwellers International • (Italian Democratic Socialists), a political party • Software Design Inc. • Spiritual Directors International, supporting spiritual direction • Steel Dynamics, Inc., a steel producer, Indiana, US.A. ==In science and technology==

Computing and telecommunications • Serial data input in the Serial Peripheral Interface bus • Serial digital interface for sending video signals over coaxial cable • Single document interface, a style of graphical user interface • Software-defined infrastructure, with no human intervention • Spatial data infrastructure • Standard Disk Interconnect, a DEC standard • Statistical Design Institute's SDI Tools for Microsoft Excel • System Deployment Image, a Microsoft disk image file format Medicine • Sulfadimidine, an antibiotic Other uses in science and technology • Selective dissemination of information • Silt density index in reverse osmosis systems • Smoke-developed index, the concentration of smoke emitted by a material • Spiral Dynamics Integral, a model of evolutionary development • Stand density index, of the stocking of a stand of trees • Subsurface drip irrigation • Suction Diesel Injection, a Volkswagen diesel engine == Other uses ==

• Saidor Airport (IATA code), in Madang Province, Papua New Guinea • Social Development Issues, an academic journal • Socio-Demographic Index of the Global Burden of Disease Study • State Disability Insurance of California, US • Strategic Defense Initiative, US anti-missile project