The interpreter is the "engine" that executes scripts.
OS/2 and other IBM OSs all natively support Rexx.
For other OSs you'll need to get a
third party Rexx
interpreter.
Development software:
EDIT (MS-DOS), Notepad (Windows), E (OS/2), or any
other ASCII editor will do.
Like most scripts, a Rexx script is an ASCII text file with a
.cmd (OS/2) or .rex
(other OSs) extension.
Rexx on its own hardly has any OS related functionality,
so you may want to install
RexxUtil and W32Funcs
too.
Help files:
Regina and (Open) Object Rexx come with their own documentation in HTML and/or PDF.
RexxInfo.org provides a long list of
Rexx tutorials.