Apache 2.2.22 |Operating System:Ubuntu

   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 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.

PHP 5.3.10-1ubuntu3.17

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

G Suite

   formerly Google Apps for Work and Google Apps for Your Domain is a brand of cloud computing, productivity and collaboration tools, software and products developed by Google.