Rexx

Rexx (restructured extended executor) is a high-level programming language developed at IBM by Mike Cowlishaw. It is both proprietary and open source, with many different versions available for many types of computers. People use Rexx to write small programs called scripts, to create shortcuts called macros, and to build larger applications.

Rexx works well in many different places. It is the main scripting language in some operating systems like OS/2, MVS, VM, and AmigaOS. It is also used to make macros in programs such as SPF/PC, KEDIT, THE, and ZOC. If you have the right tools installed, Rexx can work with Windows programs too.

A Rexx script is linked to a Rexx interpreter when it runs. On big IBM mainframe computers, these scripts are sometimes called EXEC files. On OS/2, Rexx scripts use the ".cmd" file ending, just like other scripts. On Linux, Rexx scripts usually start with a special line called a shebang. Each application that can use Rexx macros has its own rules for how those macros are named.

Name

Originally, the language was called REX, short for Reformed Executor. Later, an extra "X" was added to avoid confusion with other products. The name was written in all uppercase letters. Both editions of Mike Cowlishaw's first book on the language used all-caps, REXX, though the cover graphic sometimes used mixed case. His book on NetRexx also used mixed case but kept all caps on the cover graphic, NETREXX. In 1984, the system product used an expansion that matched the abbreviation, REstructured eXtended eXecutor.

History

pre–1990

Mike Cowlishaw created Rexx in his free time between March 1979 and mid-1982. He wanted to make a simpler language to replace EXEC and EXEC 2. Rexx was first shown publicly in 1981 at a conference in Houston, Texas, and became an IBM product in 1982.

Over the years, IBM included Rexx in many of its operating systems like VM/CMS, MVS TSO/E, IBM OS/400, and others. Rexx was also made available for many other systems, including Novell NetWare, Windows, Java, and Linux.

Since 1990

In 1990, the first independent Rexx meeting was organized, leading to the creation of the Rexx Language Association. Meetings have been held every year since then.

In 1992, two popular open-source versions of Rexx were created for Unix and Windows. More versions of Rexx have been developed for many different systems over the years. In 1996, a standard for Rexx was published by the American National Standards Institute.

In 2004, IBM announced plans to release their Object REXX under an open license. In 2005, the first public version of Open Object Rexx was released, allowing Rexx to be used for programming Windows and applications. In 2019, a meeting celebrated the 40th anniversary of Rexx in England, where it was first created.

Toolkits

Rexx has several helpful tools that make it easier to use. RexxUtil is a package that helps with files, folders, and system tasks. Rexx/Tk is a graphics toolkit that works like Tcl/Tk. RexxEd is an integrated development environment made for Windows. There are also tools like RxSock for network communication, and a Rexx interpreter that works on the Windows command line and in DOS.