I personally believe that a (perlishly) OT solution may be given in terms of Scilab since the latter is "free enough" - if your concern is to only have to restrict to people holding a regular MATLAB license. In fact, I don't even know Scilab, but for the fact that it's similar in functionality to MATLAB, and its syntax is largely based on that of the latter, although the two are known not to be completely compatible. However "there is a converter included in Scilab for MATLAB=>Scilab Conversions." Thus that may be an option.