SDI

SDI may refer to:

• SCUBA Diving International
• Serial Digital Interface (standard used in professional video equipment)
• Single document interface
• Slum Dwellers International
• Software Development Institute
• Spatial Data Infrastructure
• Standard Drive Interconnect (minicomputer interface standard by DEC)
• State Disability Insurance (as paid in California, New York State, or New Jersey, in the USA)
• Strategic Defense Initiative (U.S. anti-missile project under Ronald Reagan dubbed "Star Wars")
• Subsurface drip irrigation (also sometimes referred to as SSDI)
• S.D.I. (video game), a computer game and an arcade game
• Silt Density Index (see reverse osmosis systems)
• Socialisti Democratici Italiani, the Italian Democratic Socialists, an Italian political party
• Suction Diesel Injection, a range of diesel engines by the Volkswagen Group for use in cars and vans
• System Deployment Image (Microsoft bootable disk image)
• Smoke-developed index