user language revisions,



there are a number of designs that postdate the Macsyma design.
Ones that come to mind ..
Common Lisp
Maple
Mupad
Mathematica
Axiom, Fricas
Mathcad
Matlab "objected oriented"/  symbolic toolkit
python
Sage

While designing a language by committee is perhaps not ideal, designing 
a language
in ignorance of history (while traditional) is certainly a bad idea.

RJF