(MatFileReader on: (StandardFileStream readOnlyFileNamed: 'test.mat') binary) decode.
This will answer a Dictionary with workspace variable names as keys and MxArray as values which are essentially stubs by now. With a visitor pattern or by subclassing MatFileReader, it is possible to map the values to other Smalltalk classes.
Code repository is on squeaksource, http://www.squeaksource.com/STEM.html
MCHttpRepository location: 'http://www.squeaksource.com/STEM' user: '' password: ''.
STEM stands for Smalltalk Tools for Engineering and Mathematics (or Squeak Tools if you're tainted). The name is short, close to the main acronym for Science Technology Engineering Mathematics, and otherwise have quite many meanings (http://en.wikipedia.org/wiki/Stem) . I think I will use it by now.
I've not assembled any MonticelloConfigurationMap nor prepared any Metacello ConfigurationOfSTEM, so by now you'll have to install all the packages in this repository by yourself.
Note that STEM is not a concurrent of Polymath (http://github.com/PolyMathOrg/PolyMath). Polymath is for Pharo, and I don't yet use Pharo, I'm far more fluent in Squeak. License is MIT, and volunteers for porting/integrating into Polymath are welcome if the library sound interesting enough. I just ask to have a little respect for authorship, if ever the environment still permits it.