Trademark A high-level device-independent page description language developed by Adobe Systems Inc. It is a de facto graphical device interface standard. PostScript accurately defines pages of text and graphics, which can be rendered at a variety of resolutions. Support for PostScript is often incorporated into the output device. See also encapsulated PostScript, PDF.

http://www-cdf.fnal.gov/offline/PostScript/BLUEBOOK.PDF The PostScript introductory tutorial and cookbook

http://partners.adobe.com/public/developer/en/ps/PLRM.pdf The PostScript language reference (3rd edition)