Menu compiler
Control panel compiler
rapid prorotyping
X11/NeWS
  Supports portable X11 extensions

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* Network based window server
** A window server managers the resources of the workstation
  Screen
  Keyboard
  Mouse
  Etc...
** Distributed window system
** Remote procedure call
** Extension language versus a fixed protocol
** Efficient compressed byte stream format used for communication
** Scenario
A client connect with the NeWS server over the network. 
This starts up a lightweight PostScript process in the NeWS server
with its own local context. 
It then customizes the NeWS server by loading code defining PostScript
functions and data structures, which implement the client's user
interface and communications protocol. 

* PostScript language
** Extensibility is the key issue
** Easy to change the user interface
** Increases performance
** Crucial in a distributed environment
  Makes efficient use of network bandwidth
  Device independance is important in a heterogeneous environment
** Interactive programming environment

* Window System
** Extensions
*** Canvases
*** Processes
*** Monitors
*** Events
*** Color
*** Garbage collector

** Implemented in PostScript
*** Reasons for PostScript:
  High level programming language:
    Data structures
    program=data
    execution state
    Object oriented programming package
  High level graphics model:
    Stencil/Paint: simple, powerful.
    Device independant
    Portable clients

** Object oriented toolkit
*** Advantages
  Easy to customize the user interface
  Toolkit runs in server
    Good interactive response
    Makes efficient use of network
    Toolkit not part of each client.
    Clients share the same code.
    modular UI componants, interchangable at run time
*** Classes
  Windows
  Menus
  Widgets


** Client interface
  Remote procedure call
  Application specific protocols

** Desk accessories

* Applications

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