John Warnock and PostScript

Zusammenfassung

John Warnock spent his career solving the same problem in successively more ambitious forms: how to describe a page so that any output device could reproduce it accurately. At Xerox PARC he developed a page description language that Xerox declined to commercialize. He left, founded Adobe Systems with Chuck Geschke, and spent ten years building PostScript — the language that made desktop publishing possible — and then PDF — the format that made document distribution across devices and operating systems reliable. Adobe became the defining software company for creative professionals, and Warnock’s two inventions became infrastructure invisible to most of their users but essential to all of them.

The Graphical Page Problem

John Edward Warnock was born on October 6, 1940, in Salt Lake City, Utah. He studied mathematics at the University of Utah, completing a BS (1961) and PhD (1969) — his dissertation, supervised by Ivan Sutherland, was on computer graphics and hidden surface elimination. Utah was one of the world centers of early computer graphics research, and Warnock’s training was in the problem of representing and rendering visual images computationally.

After Utah, he worked at Evans & Sutherland (the graphics hardware company founded by Sutherland and David Evans), then joined Xerox PARC in 1978. At PARC, he worked on a project called JaM (John and Martin, for Warnock and Martin Newell) — a language for describing graphical images in a device-independent way. The idea: rather than sending a bitmap to a printer, send a description of the page that the printer could render at its own resolution. A 300 dpi laser printer and a 2400 dpi imagesetter could both produce the best output they were capable of from the same description.

This work became Interpress, a page description language that Warnock developed further at PARC. Xerox decided not to commercialize it.

Founding Adobe

In December 1982, Warnock and his manager at PARC, Chuck Geschke, resigned and founded Adobe Systems — named after the Adobe Creek behind Warnock’s house in Los Altos, California. They had negotiated the rights to develop a commercial version of their page description ideas, leaving the Interpress work at Xerox.

They designed PostScript from scratch — not a direct port of Interpress but a new language informed by it, with several key improvements. PostScript was a full programming language based on stack-based computation (like FORTH), with graphics primitives for drawing paths, curves, and text at arbitrary positions on an abstract page coordinate system:

%!PS
% PostScript — a stack-based page description language
72 72 moveto              % move to (72, 72) — 1 inch from origin
288 144 lineto            % draw line to (288, 144)
stroke                    % render the path

/Times-Roman findfont     % get Times-Roman font
24 scalefont setfont      % scale to 24 points, set as current font
100 100 moveto            % position
(Hello, World!) show      % render text
showpage                  % print the page

PostScript was device independent — a PostScript program described a page in abstract coordinates; the interpreter on the printer translated this to specific dots at whatever resolution the device supported. It was resolution independent — type and curves remained sharp at any output size. And it was a full programming language — PostScript programs could contain loops, conditionals, and procedures, enabling complex effects.

The Apple Alliance and Desktop Publishing

In 1983, Steve Jobs visited Adobe and licensed PostScript for Apple’s LaserWriter printer (1985). The LaserWriter combined PostScript, a 300 dpi laser engine, and Apple’s networking (AppleTalk) to produce letter-quality output from Macintosh computers. Combined with Aldus PageMaker (Paul Brainerd, 1985) — page layout software designed for the Macintosh — and PostScript-compatible fonts from Adobe Type Manager, the LaserWriter enabled desktop publishing.

The transformation was swift and complete. Before 1985, producing printed materials required professional typesetting equipment costing hundreds of thousands of dollars and operators trained for years. After 1985, a Macintosh, a LaserWriter, and PageMaker could produce output indistinguishable from professional typesetting at a fraction of the cost. The typesetting industry effectively ceased to exist within a decade.

Adobe Type Manager and Font Wars

PostScript’s device independence required device-independent fonts — typefaces described as mathematical outlines rather than bitmaps. Adobe developed Type 1 PostScript fonts and controlled the format tightly, charging substantial licensing fees. Microsoft and Apple responded with TrueType (1991) — an alternative outline font format that came with Windows and Mac OS without licensing fees. The “font wars” were partly a business dispute and partly a technical one: TrueType was more accessible; Type 1 was preferred by professional typographers for print quality. OpenType (Adobe/Microsoft, 1996) eventually merged the two into a single format.

PDF: From PostScript to Portability

In 1991, Warnock proposed “The Camelot Project” — a system to allow electronic documents to be created, transmitted, and printed reliably across different computers and operating systems. The problem: a PostScript file assumed the existence of specific fonts, PostScript operators, and a printer interpreter. Sending PostScript between organizations was unreliable; the receiving printer might not have the required fonts, and PostScript programs could produce different output on different interpreters.

The solution was PDF (Portable Document Format) — a format that embedded everything a document needed: fonts, images, page descriptions. A PDF looked identical on any device that could display it, regardless of what fonts or software were installed.

Acrobat 1.0 shipped in June 1993. The initial reception was muted — Acrobat Reader was free but Acrobat itself (the creation tool) was expensive, and the internet was not yet common enough to make electronic document distribution compelling. Adobe made Acrobat Reader free to download in 1994, accelerating adoption.

PDF became the universal format for document exchange: government forms, academic papers, legal filings, technical manuals. Its adoption was accelerated when the U.S. government, European Union, and major corporations standardized on it for official documents. ISO 32000-1 (2008) standardized PDF as an open format, removing Adobe’s proprietary control while standardizing the specification.

Warnock served as Adobe’s CEO until 2000 and co-chairman until 2017. He died on August 19, 2023, in Salt Lake City, at eighty-two.

Dead End: PostScript as a Computing Platform

PostScript’s status as a full programming language — Turing complete, with the full power of a stack-based programming environment — was exploited by researchers and artists who wrote PostScript programs as creative works: fractal generators, algorithmic art, and even text-based adventures entirely in PostScript. The language was capable of far more than page description.

The Power That Nobody Used

PostScript’s programming capabilities were an accident of design rather than a deliberate feature: the language needed to be expressive enough to describe complex page layouts, and a full programming language was the simplest way to achieve this. But almost no one wrote general PostScript programs. The computational power was there, but the ecosystem — development tools, debuggers, libraries — was not. PostScript’s domain remained page description; its programming capabilities were an interesting curiosity, occasionally useful and rarely exploited.

The desktop publishing revolution PostScript enabled is covered in The Desktop Publishing Revolution.