The goals of this architecture include:
 * Absolutely uncompromised output quality
 * Speed, memory efficiency, and other related performance goals
 * Ability to work smoothly with Postscript printers, fonts, and other
   resources
 * A screen display derived from the Canvas
 * An extension path for a wide variety of Unicode scripts
 * An extension path for a richer set of graphics operators than Postscript
   supports, especially transparency
 * To make life as easy as possible for application developers