ANSI X3J18
   Standard for "Programming Language REXX"
   http://www.rexxla.org/Standards/standards.html

CGI Scripts in REXX and Perl
   A guide by Les Cottrell.
   http://www-slac.slac.stanford.edu/slac/www/resource/how-to-use/cgi-rexx/

IBM BookManager BookServer Library
   All IBM Rexx manuals and redbooks.
   http://publib.boulder.ibm.com/cgi-bin/bookmgr/FINDBOOK?filter=rexx

IBM Redbooks
   Search results for REXX.
   http://publib-b.boulder.ibm.com/cgi-bin/searchsite.cgi?query=rexx

Jim Barry's Rexx Tutor
   Base on author training course at Computer Associates Training centre in Slough.
   http://www.kyla.co.uk/other/rexx1.htm

Kilowatt Software: Classic Rexx Tutorial
   Detailed language introduction.
   http://www.kilowattsoftware.com/tutorial/rexx/

Rex Swain's REXX Summary
   Summary of REXX Functions, Syntax, Symbols, Operators, and Instructions
   http://www.rexswain.com/rexx.html

SAA CPI REXX Level 2 Reference
   Old manual defining Rexx in the context of Systems Application Architecture.
   http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/E04A2A01/CCONTENTS

Six Rules of Thumb for Rexx
   This article gives six "rules of thumb" that should help get started in REXX if you already know C or Pascal (or, really, any of the children of Algol).
   http://www.uic.edu/depts/accc/software/regina/rexxrule.html