I have, after successfully asking the author to change the license of
CMask to one compatible with csound-extended, ported Andre Bartetzki's
CMask program to WebAssembly and it now is part of the WebAssembly
build of csound-extended.

A live demo can be viewed at
https://gogins.github.io/csound-extended/cmask.html.

This little project has been instructive for me. First, I found it is
fairly easy to port existing C/C++ algorithmic code to WebAssembly and
it incorporate the results into csound-extended. Second, just as
expected, anything with a JavaScript interface will work with anything
else with a JavaScript interface. Third, currently the integration of
multiple WebAssembly modules in one Web page is not possible without
some hacking.

In this case, I simply built CMask as a WebAssembly library and linked
it into the csound-extended module. In other cases, it is possible to
load different WebAssembly modules in different function scopes (you
can't do that simply by using a different