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