Windowed Modern – Floating Video от FrederickCampbell

Windowed Modern replaces website fullscreen requests with four useful options:

• Windowed — moves the current tab into a separate popup-style Firefox window.
• In-window — expands the player across the full Firefox webpage area.
• Fullscreen — uses Firefox’s normal native fullscreen mode.
• Picture-in-Picture — opens compatible videos in Firefox Picture-in-Picture.

This Firefox-focused fork improves support for nested iframes, custom embedded players, web components, and Shadow DOM-based video players.

Windowed Modern is based on the original GPLv3 “Windowed” extension by Michiel Dral.

Original project:
https://github.com/dralletje/Windowed

Maintained fork:
https://github.com/FrederickCampbell/Windowed