HSTS - Browser HTTPS Only

   The HTTP Strict-Transport-Security response header (often abbreviated as HSTS) lets a web site tell browsers that it should only be accessed using HTTPS, instead of using HTTP for 31536000 seconds

Vary Header check for User-Agent

   When using the Vary: User-Agent header, caching servers should consider the user agent when deciding whether to serve the page from cache

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.

SPF

   The Sender Policy Framework (SPF) is an email-authentication technique which is used to prevent spammers from sending messages on behalf of your domain. With SPF an organisation can publish authorized mail servers.

Google Plus

   Google+ was an Internet-based social network owned and operated by Google. The network was launched on June 28, 2011 in the attempt to challenge other social networks and for a time linked other Google products like Blogger and YouTube.

AddThis

   AddThis free website tools include share buttons, targeting tools and content recommendations help you get more likes, shares and followers

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.

Google Hosted Libraries

   The Google Hosted Libraries is a stable, reliable, high-speed, globally available content distribution network for the most popular, open-source JavaScript libraries.

jquery 1.6.0

   JavaScript library for DOM operations

Facebook SDK

   The Facebook SDK for JavaScript provides a rich set of client-side functionality

Twitter API

   You can access Twitter via the web or your mobile device. To share information on Twitter as widely as possible

PHP 5.6.40

   PHP: Hypertext Preprocessor is a general-purpose programming language originally designed for web development.

PayPal Checkout

   PayPal Checkout, formerly known as PayPal Express Checkout, is a tool made for online sellers. It allows customers to buy goods or services easily, without the need to input their shipping and billing details.