nginx [engine x] is a HTTP server and mail proxy server written by Igor Sysoev.
The DOCTYPE is a required preamble for HTML5 websites.
This page contains a meta robots tag which tells search engines and robots to index or not index the page.
Meta Keywords are a specific type of meta tag that appear in the HTML code of a Web page and help tell search engines what the topic of the page is.
These websites are related to gray-world.net in terms of content, traffic and structure