HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
SoundCloud widget gives you the ability to upload, manage and share tracks.
Vimeo is a video hosting, sharing and services platform. Vimeo operation an ad-free basis by providing subscription plans.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.