Project information : nestopia/COPYING at master · 0ldsk00l/nestopia · GitHub
License:GNU GENERAL PUBLIC LICENSE Version 2
Upstream has been contacted:
There is a new update: “To celebrate the '90s, Nestopia’s Linux port was moved to FLTK and oldschool OpenGL 1.x.”
With that update, the emulator goes fullscreen with no problems on any GTK based DE. (Version 1.50 has a lot of problems with that), and stills works perfect under other DE´s, as usual. Hope to see the flatpak updated. Thanks.