"The original OpenStep system developed by NeXT Software contained a number of object-oriented frameworks written in the Objective-C language. Most developers who used these frameworks wrote their code in Objective-C.
In recent years, the number of developers writing Java code has increased dramatically. For the benefit of these programmers, Apple Computer has provided Java APIs for these frameworks: Foundation Kit, AppKit, WebObjects, and Enterprise Objects. They were made possible by using techniques described later in this document. You can use these same techniques to expose your own Objective-C frameworks to Java code."