The desktop publishing point (DTP point) or PostScript point is defined as 1⁄72 or 0.0138 of the international inch, making it equivalent to 352.7 µm. Twelve points make up a pica, and six picas make an inch. A separate typographic or printer's foot is not needed anymore.
This specification was developed by John Warnock and Charles Geschke when they created Adobe PostScript. It was adopted by Apple Computer as the standard for the display resolution of the original Macintosh desktop computer and the print resolution for the LaserWriter printer.
In 1996, it was adopted by W3C for Cascading Stylesheets (CSS) where it was later related at a fixed 4:3 ratio to the pixel due to a general (but wrong) assumption of 96 px/in screens.
The concepts of the PostScript language were seeded in 1976 when John Warnock was working at Evans & Sutherland, a computer graphics company. At that time John Warnock was developing an interpreter for a large three-dimensional graphics database of New York harbor. Warnock conceived the Design System language to process the graphics.
Concurrently, researchers at Xerox PARC had developed the first laser printer and had recognized the need for a standard means of defining page images. In 1975-76 Bob Sproull and William Newman developed the Press format, which was eventually used in the Xerox Star system to drive laser printers. But Press, a data format rather than a language, lacked flexibility, and PARC mounted the Interpress effort to create a successor.
In 1978 Warnock left Evans & Sutherland and joined Xerox PARC to work with Martin Newell. They rewrote Design System to create the interpretive language, J & M or JaM (for "John and Martin") which was used for VLSI design and the investigation of type and graphics printing. This work later evolved and expanded into the Interpress language.
Warnock left with Chuck Geschke and founded Adobe Systems in December 1982. They, together with Doug Brotz, Ed Taft and Bill Paxton created a simpler language, similar to Interpress, called PostScript, which went on the market in 1984. At about this time they were visited by Steve Jobs, who urged them to adapt PostScript to be used as the language for driving laser printers.