I brushed up my knowledge about Rexx from this page ...
<http://www.mindspring.com/~dave_martin/what_is_rexx_.html>
... and concluded that a (very) good substitute for Mac (and other) users
might be Lua. Get a precompiled Lua 3.1 application or library for the Mac
OS from this page ...
<http://www.lmf-di.puc-rio.br/~terra/links4.html>
... or get the very latest source code (3.2) from this page ...
<http://csg.uwaterloo.ca/~lhf/lua/download.html>
Lua is a very small, very fast, extensible language. If for some reason
you should need some more high level features right away, like internet
send/receive anthing, you could take a look at REBOL,
<http://www.rebol.com/nutshell.html>.
/Jon