NetRexx, a programming language designed to be easier to learn and use than Java, combines the syntax of the Rexx language and the semantics of Java. Rexx is a script language, developed at IBM, that is popular among IBM's corporate mainframe system users. NetRexx, developed by Rexx's inventor, Mike Cowlishaw, superimposes Rexx's ease-of-use on the object-oriented programming concepts of Java - classes, methods, and properties. NetRexx source code statements are compiled into Java source statements, which are then compiled into Java bytecode that can be run in any computer operating system that includes a Java virtual machine (JVM). Thus, NetRexx programs can be run in Windows, OS/2, MVS, UNIX-based systems - in short, almost any operating system that supports the Java 1.1 toolkit and compiler and includes the JVM.
According to IBM, a study shows that the Java source for a typical class has about 35% more lexical tokens and requires about 20% more keystrokes than it would in NetRexx. NetRexx has equivalent classes for all Java classes.