Postscript

PostScript is a page description language developed by Adobe Systems in the early 1980s. It describes the text and graphical content of a page in a device-independent way, allowing printers or displays to render a page consistently across devices.

The language is stack-based and postfix, with operators that manipulate graphics state, paths, and text. A page is described using coordinates, transformation matrices, and graphical primitives such as lines, curves, and filled shapes. PostScript supports color models, shading, and image embedding. Fonts are integral, with Type 1 and Type 3 technologies; units are points (1 point = 1/72 inch).

PostScript exists in several levels. Level 1 introduced basic features; Level 2 added imaging and efficiency enhancements; Level 3 expanded color support and performance. Encapsulated PostScript, or EPS, is a subset intended for embedding graphics in other documents. PDF, a later descendant, is designed for reliable portable document interchange.

The format was widely adopted in desktop publishing, especially after the Apple LaserWriter’s release in 1985, enabling high‑quality scalable fonts and graphics from page‑layout software. Although PDF has largely supplanted PostScript for document interchange, PostScript remains in use as a page description language in printers and workflows.

Because PostScript is a Turing‑complete programming language, a file can contain executable code, which raises security considerations in untrusted environments. Modern workflows often rasterize or convert PostScript to PDF to reduce risk.