Hi again,
does applications which were compiled under OpenStep for MACH 4.2 run under NeXTStep 3.3 (upward compatibility) ?
With Regards,
Martin
OpenStep came after NextStep. OpenStep comes with a set of NextStep libraries for backwards compatibility. But any application compiled using the OpenStep APIs won't work under NextStep. NextStep for example lacks the Foundation class. You can however install a copy of the NextStep developer tools under the OpenStep OS.
OpenStep was a major rewrite of the Next API as an industry standard specification. As such, a lot of the assumptions about the underlying hardware and programming environment could no longer be taken for granted. The Foundation class was created to abstract a lot of the things which were previously directly manipulated in NextStep, such as text strings, files, etc. The OpenStep developer tools come with some scripts to convert NextStep source code to an OpenStep equivalent. But going from NextStep to OpenStep is non-trivial, at least for any application more complicated than a simple "Hello World!" type app.
If you want to play with NextStep as a hobbyist, download or find a used copy of NeXTSTEP Programming, Step One: Object-Oriented Applications from Simson L. Garfinkel and Michael K. Mahoney and enjoy. If you're looking at writing for a wider audience or make money, stick to OpenStep as it converts over to Mac OS and iOS.