cdnjs is a free distributed JS library delivery service.
Drupal is a free and open-source web content management framework.
Font Awesome is a font and icon toolkit based on CSS and Less.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
OpenResty is a web platform based on nginx which can run Lua scripts using its LuaJIT engine.
WidgetWhats is a fully customizable chat widget with appearance, text, color, button style and position.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.