NetRexx is an open source general-purpose programming language. It is a variant of the REXX programming language that runs on the Java virtual machine and in addition to the common REXX features it has simplified syntax in some cases, Java-like object oriented extensions and exception handling, unlimited precision arithmetic, better internet and/or networking integration and the ability to function as either an interpreter or compile to a Java executable.
NetRexx has an interesting history, when IBM was writing their own Java stack on OS/2 in 1995, Mike Cowlishaw implemented a version of REXX that would run under the Java environment, and released it in 1996. This was not only the first external language to be released under the Java system, it did not compile to Java code but to Java bytecode, so it was also the first program to take advantage of the JVM as a runtime environment rather than as a Java environment. NetRexx is written in itself rather than a Java program per se.
Note that even though the syntax is quite similar to REXX the language is in many ways quite different than "Classic REXX" so that even small programs will need to be ported to the environment.
- 1.00 (Jan 1997)
- initial release by IBM
-  - IBM's last NetRexx release, for JVM versions 1.5 and earlier.
- 3.03 (2014-06-11)
- While V3.04 works fine on OS/2, all of the OS/2 specific scripts were removed from the distribution prior to its release, you should at the least keep a copy of V3.03 handy in case you need them.
- 3.04 (2015-07-01)
- Note, any version of NetRexx appears to work under Java for OS/2. However, version 3.03 has problems with some of the Java versions delivered for IBM mainframes while versions before 3.03 have problems running on Java 8 under windows.
- 3.05 (2017-04-27)
- 3.06 (2017-12-12)
- Rexx2Nrx - Converts Classic REXX software to NetRexx - Open Source - Discontinued
- Text editor support
- Enhanced Editor - Syntax and NetRexx/Java class highlighting available as a separate download (EPMKWDS.NRX)
- jEdit - Java based editor - NetRexx 3 syntax highlighting built in - Current
The 1.x and most 2.x versions of NetRexx are released under the IBM License Agreement for IBM Employee-Written Software.
- M.F. Cowlishaw: NetRexx: An Alternative for Writing Java Classes
- M.F. Cowlishaw: The NetRexx Language - Prentice Hall 1997, ISBN 0-13-806332-X
- Peter Heuchert: Creating Java Applications Using NetRexx - IBM RedBook (SG24-2216-00) 1997, ISBN 0-7384-0435-7 
- VM/ESA Network Computing With Java and NetRexx - IBM RedBook (SG24-5148-00) 1998, ISBN 0-7384-1034-9 
- Source code snippets, archives and collections
Small programs or routines that you can integrate into your own programs or study to learn from, but are not delivered in library form.