Network-Oriented Window Systems

Until recently, high- performance graphics programs had to
execute on a computer that had a bit-mapped graphics screen directly
attached to it. Network window systems allow a program to use a
display on a different computer. Full-scale network window systems
provide an interface that lets you distribute jobs to the systems that
are best suited to handle them, but still give you a single
graphically-based user interface. (The most widely-implemented window
system is X. A protocol description is available from MIT's Project
Athena. A reference implementation is publicly available from MIT. A
number of vendors are also supporting NeWS, a window system defined by
Sun. Both of these systems are designed to use TCP/IP.)
Note that some of the protocols described above were designed by Berkeley, Sun,
other organizations. Thus they are not officially part of the Internet protocol suite.
However they are implemented
using TCP/IP, just as normal TCP/IP application protocols are. Since the protocol
definitions are not considered proprietary, and since commercially-support
implementations are widely available, it is
reasonable to think of these protocols as being effectively part of the Internet suite.
 
Also note that the list above is simply a sample of the sort of services available through
TCP/IP. However it does contain the majority of the "major" applications. The other
commonly-used protocols tend to be
specialized facilities for getting information of various kinds, such as who is logged in,
the time of day, etc. However if you need a facility that is not listed here, we encourage
you to look through the current edition of Internet Protocols (currently RFC 1011), which
lists all of the available protocols, and also to look at some of the major TCP/IP
implementations to see what various vendors have added.