youtube-chapters is a vanilla JavaScript plugin to generate interactive chapters for long Youtube videos. So that the visitors are able to quickly jump between multiple segments of your video by clicking the chapter links.
vLite.js is a native JavaScript plugin designed for creating custom HTML5 and Youtube Video players with your own styles.
MediaBox is an easy and lightweight vanilla JavaScript library which displays and plays Youtube or Vimeo videos in a fullscreen, responsive, modal-like lightbox popup.
Yet another Youtube lazy loader that delays the loading of Youtube video player to improve the performance of your web page.
llyv.js is a Youtube Video lazy load library which allows the user to load Youtube Video Players on demand.