OpenStep Demonstration
Volume Number: 13
Issue Number: 5
Column Tag: OPENSTEP
Building an OpenStep Application
by Michael Rutman, independent consultant
Is it really as easy to program in OpenStep
OpenStep and NEXTSTEP
In 1985, Steve Jobs left Apple and formed NeXT. He found the latest technologies and
brought together a team of developers to turn the newest theories into realities. To
verify the new technologies, during development Steve would often stop development
and have the entire team use the system they were creating. Several existing apps
were created during these day or week long kitchens. More importantly, each
developer knew how the framework would be used. If developers had a hard time using
an object during a kitchen, they knew they had to rework that object.
The system they created was called NEXTSTEP. NEXTSTEP has several layers, and each
layer was state of the art in 1985. In the 12 years since Steve picked these
technologies, the state of the art may have moved, but not advanced.
The underlying OS is a Mach mini-kernel running a unix emulator. For practical
purposes, Mach is a flavor of BSD unix. However, the Mach mini-kernel offers
programmers a rich set of functionality beyond what unix provides. Most of the
functionality of Mach is wrapped into the NEXTSTEP framework, so programmers get
the power and flexibility of Mach with the ease of use of NEXTSTEP.
Sitting on top of Mach is Display Postscript. Postscript, the language of printers, is a
nice graphics language. NeXT and Adobe optimized Postscript for displaying on the
screen and produced a speedy and powerful display system. NeXT's framework hides
most of the Postscript, but if a programmer wants to get into the guts, there are
hooks, called pswraps, to work at the Postscript level.