HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Open Graph is a protocol that is used to integrate any web page into the social graph.
RequireJS is a JavaScript library and file loader which manages the dependencies between JavaScript files and in modular programming.
UIKit is the framework used for developing iOS applications.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.