Short for Restructured Extended Executor, an interpreted, structured, procedural script programming language created by IBM's Mike Cowlishaw that allows programs and algorithms to be written in a clear structured way. It was designed so that it would be truly easy to use for both professionals and casual users and was designed to work in several diverse application areas -- such as personal programming, command processing, application macro processing and application prototyping -- where different languages are typically used. It is, however, designed to be platform-independent.
Even though Rexx is not BASIC, it can be used to write simple programs and large robust programs and can be used for many of the programs for which BASIC would otherwise be used.
Rexx evolved between the years 1979 and 1982 and, in 1983, IBM made Rexx the standard System Product interpreter for CMS in VM/SP and VM/XA. IBM selected Rexx as its SAA Procedures Language in 1987 and brought the language to all of its operating platforms, including MVS, VM, OS/400, AIX and OS/2. Today, Rexx is available in either commercial form or as freeware for operating systems including Amiga, MS/PC-DOS, most UNIX systems, VMS, 16-bit Windows, Macintosh, Windows NT and all IBM systems.