FullCalendar and its iCalendar plugin 6.1.19: MIT license. https://github.com/fullcalendar/fullcalendar/tree/v6.1.19
ical.js 2.2.1: MPL-2.0, distributed without modifications. Corresponding source: https://github.com/kewisch/ical.js/tree/v2.2.1
License texts are included in this directory.
Luxon 3.7.2 and FullCalendar Luxon3 plugin 6.1.19: MIT licenses. https://github.com/moment/luxon/tree/3.7.2 and https://github.com/fullcalendar/fullcalendar/tree/v6.1.19