As looking at the web page, you can install on:
Windows, MacOS X, Linux
There is no way .NET framework is build for MacOS X, Linux.
It is pointless, to buil MuPad with .NET especaly for windows, but corp can use c++ cross-platform files, for maintaing is a lot easier, a lot cheaper, and the same techonlogy. And betwen them is very little diffrence in code. The Only big diffrence is Prebuild libraries for specific OS.