is compatible license of has website homepage GNU GPL v3 GNU GPL v2 LPPL v1.3c https://latex-project.org/lppl/lppl-1-3c.html LPPL v1.3 is a free software license (by the defintion of the GNU Project), with less stringent requirements on distribution than LPPL 1.2. It is still incompatible with the GPL because some modified versions must include a copy of or pointer to an unmodified version.Software projects other than LaTeX rarely use it. Latex Project Public License v1.3c Modified from http://en.wikipedia.org/wiki/LaTeX_Project_Public_License, accessed 12 June 2013; modified from http://www.gnu.org/licenses/license-list.html, accessed 12 June 2013. LPPL