REXX rocked. It was included in IBMDos 7, (and OS/2 of course) and was as powerful a scripting tool as you'd want back in the day. What I thought was great was that you could write a Rexx script that would run on a PC, and would run unmodified on a mainframe as well.
It ticked me off to no end that MS included a REXX (Regina) interpreter with NT4, but not W2K.