PS1, Ps 1, PS-1, PS/1 or PS One may refer to: Arts and entertainment Ponniyin Selvan: I, an Indian Tamil language period action drama film Technology "$PS1", "Prompt String 1" the environment variable in a command-line interface which specifies the command prompt IBM PS/1, IBM Personal System/1 series of home computers Pan-STARRS' first telescope, called PS1 PostScript Type 1 Font Prosteyshiy Sputnik 1, the first artificial Earth satellite .ps1, the extension of a Microsoft PowerShell script file Video gaming PlayStation (console), video game console released by Sony in 1994 PS One (console), a miniature version of the original PlayStation released in 2000 Phantasy Star (video game), the first in the Phantasy Star series PlanetSide (video game), the first in the PlanetSide MMOFPS video game series Other uses Photosystem I, the second photosystem in the photosynthetic light reactions of plants MoMA PS1 (derived from "Public School One"), American contemporary art institution The name and designation for several public schools in the New York City Department of Education; see List of public elementary schools in New York City Psalm 1 from the Judeo-Christian Book of Psalms The boxcar in the PS line of post-war standardized freight cars from Pullman-Standard