cdnjs is a free distributed JS library delivery service.
Discourse is an open-source internet forum and mailing list management software application.
Google Analytics is a free web analytics service that tracks and reports website traffic.
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.
OpenResty is a web platform based on nginx which can run Lua scripts using its LuaJIT engine.
Unpkg is a content delivery network for everything on npm.