nginx [engine x] is a HTTP server and mail proxy server written by Igor Sysoev.
LiteSpeed web server is a light-weight server which conserves resources without sacrificing performance, security, compatibility, or convenience. It is capable of handling multiple concurrent clients with minimal memory consumption and CPU usage.
PHP is a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML.
Open graph description entity tag
When running in a browser on a mobile phone, "format-detection" meta tag determines whether or not telephone numbers in the HTML content will appear as hypertext links. The user can click a link with a telephone number to initiate a phone call to that phone number.