The NeWS Book leads the technical reader through the discovery of a revolutionary window system: the Network extensible Window System, developed by Sun Microsystems. Independent of computer hardware and systems software, NeWS has been ported to a number of platforms and licensed to many computer vendors and software developers. NeWS will be part of the standard UNIX distribution from AT&T in the future as it is combined with the well-known X Window System from MIT in the X11/NeWS product. The specifications are in the public domain. Based on the popular PostScript page description language, NeWS provides a uniquely extensible interpretive programming environment for application developers in a networked graphics and window system environment. Networking is integral to NeWS; NeWS-based programs may span a heterogeneous set of distributed sites. NeWS is the first system to extend the PostScript language's already wide acceptance in printing applications into the realm of graphics and window-based applications. The NeWS Book is intended for a technical audience who may or may not have experience with window system design and programming. It gives practical examples of how to write PostScript programs, that implement interactive user interface techniques, while also exploring how the advanced imaging of the PostScript language model applies to the display as well as the printer. UNIX, NeWS, and graphics programmers, developers of graphical applications, computer science students, PostScript language devotees in desktop publishing, and sophisticated end-users who want to understand leading-edge solutions in window system design all will benefit from The NeWS Book.