Extra considerations:
The license for this SoundFont is various and valid as for any individual source (see "MatrixSF - instruments, licenses.txt").
You can use this sounds/instruments respecting the licenses or even create your own SoundFont from this with some modifications (fork) and publish it, but you must also indicate this in the SoundFont name (e.g. "MatrixSF (edited by Mark)", "MatrixSF Mark version"...), put the license/attribution file for the original creators and give the SoundFont for free.
The list of sources of all instruments and the corresponding licenses are ca. 99% correct, because I probably missed a few sounds due to testing from many sources. If any sound/instrument should not be in this SoundFont, please send mail at
matrix36963@gmail.com, it will be removed/replaced.