Hello *,
I am using MuPAD 2.0. By the way, I wrote TeXmacs interface to it. It was
very easy, just a few lines of code, and it is very robust. This is
because MuPAD allows one to customize everything (prompts, output
functions, ...) easily and systematically. No special cases, just general
rules. With Maxima, the situation is quite different: a dozen varieties
of prompts, input and output functions are scattered all over the code
and not easily redefinable, etc.
What about MuPAD language, it mainly follows Maple. Some good data
abstraction mechanisms (domains and categories) are inspired by Axiom.
Unlike Axiom, it is not strongly-typed, and the power of its advanced type
system is not fully used, IMHO. Its help system is based on a (slightly
modified) dvi viewer, and therefore looks good. In the TeXmacs/Maxima
case, TeXmacs is used as the help engine, and provides equally good
quality.
Best wishes,
Andrey