The Rexx Plus ™ Compiler was produced by the Dineen Edwards Group, at
19785 West Twelve Mile Rd., Suite 305, Southfield, Michigan, 48076-2553, phone
(313) 352-4288.
I had heard that they had gone out of business, but have no confirmation of
that. You could try phoning to see. (If the product is still available, a
posting here wouldn't hurt).
–Jim