SLD may refer to: Computers and technology Second-level domain, an Internet domain directly beneath the top-level domain Simple learning design 2.0, a specification used to express learning activities SLD resolution, the basic inference rule used in logic programming Stanford Large Detector (1992–1998), for the Stanford Linear Collider Superluminescent diode, a light source Soft laser desorption, a laser desorption of large molecules that results in ionization without fragmentation Graphics Single-line diagram, of a 3-phase power system Straight-line diagram of a road Styled Layer Descriptor of map layers Politics and law Democratic Left Alliance (Sojusz Lewicy Demokratycznej), a political party in Poland Statute law database, UK Transport Salford Crescent railway station, Greater Manchester, England, National Rail station code SLD Sliač Airport, Slovakia, IATA code Sutherland railway station, Sydney Sutherland, Australia, station code SLD Other uses SLD glass, with low dispersion Specific learning disability, disorders intrinsic to an individual Supercooled Large Droplet, a type of atmospheric icing condition Delta8-fatty-acid desaturase, an enzyme