System 7 is the newest Macintosh
operating system. Like MS-DOS on
the PC, it controls the central
processor and coordinates your
keyboard and monitor. It also creates
the mouse interface or "desktop"
screen you see when you turn on the
Mac, and helps you create and delete
files, store files on disk, and find
them again when you need them.
System 7 is much more, however.
One of System 7's magic tricks is the
way it integrates simple applications
using what Apple calls Inter-
Application Communication, or
"Publish-and-Subscribe." Simply put,
applications and lets them "talk" to
each other. By sharing information,
individual applications dedicated to
a single function, like drafting or
number-crunching, can combine to
form hybrid applications that