Display PostScript

Display PostScript
Name	Display PostScript
Developer	Adobe Systems
Released	1989
Latest release version	(proprietary)
Operating system	Unix, NeXTSTEP, VMS
Genre	2D graphics, imaging model, page description

Display PostScript is a graphics system that extends the PostScript imaging model to raster display devices, enabling the same device-independent drawing language used for printing to render interactively on screens. It was designed to integrate with workstation environments and window systems to provide high-fidelity typography, scalable graphics, and device-independent rendering for applications in publishing, typesetting, and graphical user interfaces. Major computing vendors, workstation manufacturers, and publishing houses evaluated or adopted the technology during the late 1980s and early 1990s.

Overview

Display PostScript provided an implementation of the PostScript language optimized for on-screen rendering, combining the Printer language semantics of PostScript Level 2 with display-oriented services. It aimed to bridge software like Adobe Illustrator, QuarkXPress, Aldus PageMaker, and Adobe Photoshop with workstation families such as Sun Microsystems workstations, NeXT machines, and systems from DEC and Silicon Graphics. The system exposed an API layered with concepts familiar from X Window System, OpenStep, and windowing toolkits, while preserving device independence for output to printers and plotters like those from Hewlett-Packard and Linotype‑Hell.

History and Development

Development began at Adobe Systems as an effort to repurpose the PostScript language beyond printers, informed by interactions with companies such as Apple Inc., Sun Microsystems, NeXT, and Hewlett-Packard. Early demonstrations and collaborations took place alongside industry events like SIGGRAPH and National Computer Graphics Association meetings. The technology was showcased in conjunction with hardware and software vendors including Silicon Graphics, Digital Equipment Corporation, Xerox, and workstation software groups from Bell Labs. Academic and research groups at institutions like MIT, Stanford University, Carnegie Mellon University, and University of California, Berkeley explored integrations with graphics toolkits, while publishing firms such as The New York Times Company and Time Inc. evaluated it for production workflows.

Architecture and Implementation

Display PostScript implemented a resident interpreter derived from the PostScript language runtime and added tiled repainting, backing store mechanisms, and clipping optimizations to suit raster framebuffers on hardware from Intel, Motorola, and SPARC families. Integration points included server-side compositing similar in spirit to the X Window System and client-side drawing akin to OpenGL immediate mode, enabling interaction with window managers such as CDE and toolkits like Motif and Qt. Vendors implemented device drivers to map PostScript device primitives to framebuffer formats on platforms like NeXTSTEP, Ultrix, IRIX, and VMS. Memory management, font caching, and font rendering interoperated with Adobe Type Manager, ATM Light, and outline font technologies developed by foundries including Monotype Imaging and Linotype. The system accommodated color management workflows tied to ICC profiles and interoperability with desktop publishing pipelines using EPS and PDF assets.

Features and Capabilities

Display PostScript offered scalable vector rendering, true-type and Type 1 outline font rendering, anti-aliased drawing, affine transforms, stroking and filling operations, and device-independent color spaces aligned with PostScript Level 2 semantics. It supported printing fidelity by maintaining a consistent model between screen and printer output for applications like Adobe InDesign, scientific visualization tools at NASA, and CAD packages from vendors such as Autodesk. The environment provided complex path operations, Bézier curve handling rooted in mathematical formulations used in Donald Knuth’s typesetting work, and compositing operations analogous to those later standardized in PDF blending modes. Extensions facilitated interactive features found in user interfaces designed by teams at NeXT, Apple Computer, and research labs at Xerox PARC.

Usage and Applications

Adoption appeared in high-end workstations used by graphic designers, publishers, and researchers; prominent users included The New York Times, The Washington Post, academic graphics labs, and multimedia studios working with Avid Technology and Alias Research. It was embedded in systems for prepress, newspaper pagination, vector drawing programs, scientific plotting suites at institutions such as CERN and Lawrence Livermore National Laboratory, and visualization tools in industries represented by Boeing and General Electric. Integration with desktop environments influenced software stacks for NeXTSTEP and informed efforts by companies like Sun Microsystems and Silicon Graphics to provide professional graphics on UNIX workstations. Training and advocacy occurred at conferences including COMDEX, SIGGRAPH, and NAB Show.

Limitations and Decline

Despite technical strengths, Display PostScript had limitations: interpreter overhead on CPUs from the era (such as Intel 80386, Motorola 68040, and SPARCstation), complexity of integrating with existing window systems like X11, licensing costs from Adobe Systems, and competition from raster-accelerated APIs including OpenGL and evolving APIs behind Microsoft Windows NT and Apple Macintosh toolkits. The rise of PDF as an interchange format, improvements in GPU acceleration by NVIDIA and ATI Technologies, and adoption of alternative rendering systems in GNOME and KDE ecosystems reduced its prominence. Vendors migrated to hybrid models, custom rasterizers, and hardware-accelerated compositors, leading to gradual obsolescence in favor of newer imaging pipelines used by companies such as Apple, Microsoft, Google, and open-source communities around FreeType and Cairo.

Category:Computer graphics