<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
will be a superset of OpenStep
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.