OpenStep

OpenStep is an object-oriented API specification for an object-oriented operating system that uses any modern operating system as its core, principally developed by NeXT with Sun Microsystems. It is important to recognize that while OpenStep is an API specification, OPENSTEP (all capitalized) is a specific implementation of this OpenStep developed by NeXT. While originally built on a Mach-based Unix (such as the core of NEXTSTEP), versions of OPENSTEP were available for Solaris and Windows NT as well. Furthermore the OPENSTEP libraries (the libraries that shipped with the OPENSTEP operating system) are in fact a superset of the original OpenStep specification.
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<operating system> An object-oriented application programming interface (API) derived from NEXTSTEP and proposed as an open standard by NeXT in 1994.
OpenStep is the specification of the object kits of NEXTSTEP. OPENSTEP/Mach was an implementation of this specification. The original, OPENSTEP version 4.0, and really was NEXTSTEP 4. Rhapsody was the codename for Apple's Mac OS X Server, which is really NEXTSTEP 5 (it calls itself "kernel 5.3" at boot time).
OpenStep was designed to be implemented independently of the computer's operating system, hardware, and user interface. The API for Rhapsody will be a superset of OpenStep's.
When the OpenStep API is implemented for a specific platform and made into a product, it is written in uppercase, e.g. OPENSTEP Developer 4.2 for Mach, or OPENSTEP Enterprise for Windows NT and Windows 95. Versions of OPENSTEP exist for Windows 95/NT, Solaris, HP/UX, and Mach.
(1999-11-25)