Currently you either have MATLAB+Toolboxes or Octave+Packages. I always wondered whether there could be a project to create open source toolboxes that would run

Currently you either have MATLAB+Toolboxes or Octave+Packages. I always wondered whether there could be a project to create open source toolboxes that would run in MATLAB. That means no effort is needed to maintain the core language features of MATLAB (of course you would need to buy the basic MATLAB licence without the Toolboxes) in that project and all the energy is spent on developing open-source toolbox replacements (which are typically way more expensive than basic MATLAB licence).