PIP is an application with combination of screen capture API and Picture-in-Picture API, which allows you to watch videos in a floating window, so you can keep an eye on what you're watching while interacting with other sites, or applications.
https://megapictureinpicture.netlify.app
- Screen Capture API: https://developer.mozilla.org/en-US/docs/Web/API/Screen_Capture_API
- Picture in Picture API: https://developer.mozilla.org/en-US/docs/Web/API/Picture-in-Picture_API