nginx [engine x] is a HTTP server and mail proxy server written by Igor Sysoev.
Express is a fast, unopinionated, minimalist web framework for Node.js
Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient.
UTF-8 (8-bit UCS/Unicode Transformation Format) is a variable-length character encoding for Unicode. It is the preferred encoding for web pages.
Sites who has this tag are verfied by google to use WebMaster tools
The Open Graph protocol enables any web page to become a rich object in a social graph, a open protocol supported by Facebook