Yes, and it's a library that could be conceivably ported to Lisp. As Scmutils have shown, "lispy" languages with multimethods/generic functions are really suitable for building symbolic manipulation systems. So chances are that functional port to Lisp could provide a really nice interface to SymPy's functionality.

And Maxima was created before Common Lisp even existed. Steele first presented Common Lisp at a conference in 1982, and CLTL1 wasn't published until 1984.

As I recall, Maxima was first written for Franz Lisp. Older lisps like that used dynamic binding for all variables.

Uh, Macsyma was first written for Maclisp.

Yes. Perhaps I was drawing too fine a line in distinguishing Macsyma from Maxima.