GNU General Public License v3 (GPL)
Use on a web browser, such as Chrome, Firefox or Safari, without any installations, upgrades, updates, registration, sign-in and terminal commands.
Chrome or Firefox is recommended due to its performance.
Taisuke Ozaki, Yung-Ting Lee
 Y.-T. Lee, T. Ozaki, arXiv:1904.03992 [cs.HC].