OpenStep is an Application Programming Interface (API) for creating applications using the Objective-C language. It was published by NeXT Computer Inc. in 1994.
OpenStep consists of three parts:
- the FoundationKit, a library of non-graphical objects;
- the AppKit, a library of objects useful in creating graphical applications;
- and Display Postscript, an interface for drawing to the screen using the PostScript graphics language.
The OpenStep specification is available in a couple of different formats from .
The commercial successor to the OpenStep APi is Apple's Cocoa API.