Donald Knuth has indicated several times that the source code of TeX has been placed into the "public domain", and he strongly encourages modifications or exper

Donald Knuth has indicated several times that the source code of TeX has been placed into the "public domain", and he strongly encourages modifications or experimentations with this source code. https://en.wikipedia.org/wiki/TeX#License https://en.wikipedia.org/wiki/TeX#License