Space Transportation System, the official name of the Space Shuttle program

STS, a Synchronous Transport Signal, part of the Synchronous optical networking communications system

Science and technology studies

SharePoint, originally known as SharePoint Team Services

Scanning tunneling spectroscopy, a microscope technique

Station-to-Station protocol, a cryptographic key agreement scheme that provides mutual authentication

Cadillac STS, a luxury car sold by Cadillac

Semipalatinsk Test Site, the primary test site for Soviet nuclear weapons

Socio-technical systems

STS, the IATA airport code for Charles M. Schulz - Sonoma County Airport

Strathcona-Tweedsmuir School, a private school in Alberta

STS (Russian television network), a Russian TV channel

Synergy Teleconferencing System, a computer bulletin board operating system

Sequence-tagged site, a gene-reference in genomics

State transition system, an abstract machine used in the study of computation

Space Tourism Society, a society focused on space tourism

Intel Science Talent Search, a research-based science competition

Microsoft Live Labs Security Token Service, a gateway to handle claims within Microsoft's Identity Metasystem

STS Relay, the speech to speech relay service available via 711 in the United States

Serviciul de Telecomunicaţii Speciale, the Romanian Special Telecommunication Service

Satanas, a Filipino-American gang

Siemens Transportation Systems, the transportation business unit of Siemens AG

Ship-to-ship Transfer, an operation where cargo is transferred between seagoing ships