In many jurisdictions, including the United States and European Union, circumventing the activation mechanism is a violation of the DMCA. The activation key system is technically a "technological
Keys found on torrent sites, forums, or keygen tools are almost always: Matlab R2009b Activation Key
First, check if your legacy code runs on GNU Octave (85%+ compatibility with R2009b syntax). Second, contact MathWorks about a legacy license – they sometimes offer steep academic or hobbyist discounts. Third, use MATLAB Online's free tier to gradually port your code to modern MATLAB. In many jurisdictions, including the United States and