PostScript: the page description language for printing and graphics

Key characteristics

• Stack-based and postfix syntax: Operators take their operands from an operand stack; expressions are written in reverse Polish notation.
• Device-independent imaging model: Coordinates, paths, strokes and fills are defined abstractly so the same file can be rendered at different resolutions.
• Procedural and extensible: The language supports loops, procedures, dictionaries and user-defined operators, allowing complex page generation.
• Font and graphics support: PostScript defines scalable outline fonts (Type 1 and Type 3 among others) and includes powerful path construction and clipping features.

History and development

PostScript was created at Adobe in the early 1980s by a team led by company founders. Adobe introduced it as a standard way for publishing systems to describe pages for output devices. Because the language itself is Turing-complete and programmable, early laser printers incorporated interpreters that executed PostScript code directly.

Versions and related formats

PostScript evolved through several levels (commonly called Level 1, Level 2 and Level 3), each adding color handling, improved performance and additional imaging operators. A closely related format is Encapsulated PostScript (EPS), a restricted subset intended for exchange of single graphics objects. Open-source interpreters and toolchains, such as Ghostscript, provide rasterization and conversion services.

Uses and practical importance

PostScript played a central role in desktop publishing and commercial printing workflows by enabling device-independent descriptions that raster image processors (RIPs) convert to bitmaps for output devices. It is commonly embedded in print jobs sent to computer printers and used to generate high-quality typography and scalable graphics for books, magazines and proofs.

Relationship to PDF and notable distinctions

Adobe later developed the Portable Document Format as a fixed-layout document format better suited for reliable electronic exchange and on-screen viewing. PDF inherits many imaging concepts from PostScript but encapsulates document structure, metadata and interactive features; it is not a general-purpose programming language in the same way. For background on the company and its technologies see Adobe.