Character Encoding :utf-8

   This website is using utf-8 character encoding in HTML , character encoding is used to represent a repertoire of characters by some kind of encoding system.

mathjax 2.7.0

   MathJax is an open source JavaScript display engine for mathematics that works in all browsers.

Cdnjs

   cdnjs is a CDN host for opensource libraries

Apache

   The Apache HTTP Server, colloquially called Apache, is free and open-source cross-platform web server software, released under the terms of Apache License 2.0. Apache is developed and maintained by an open community of developers under the auspices of the Apache Software Foundation.

Vary Header Accept-Encoding

   The Accept-Encoding request HTTP header advertises which content encoding, usually a compression algorithm, the client is able to understand. Using content negotiation, the server selects one of the proposals, uses it and informs the client of its choice with the Content-Encoding response header.