Websites using some form of Captcha technology on them.
CloudFlare is a global CDN and DNS provider that can speed up and protect any site online.
nginx [engine x] is a HTTP server and mail proxy server written by Igor Sysoev.
PHP is a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML.
The DOCTYPE is a required preamble for HTML5 websites.
Allows a website to define how a page is rendered in Internet Explorer 8, allowing a website to decide to use IE7 style rendering over IE8 rendering.
UTF-8 (8-bit UCS/Unicode Transformation Format) is a variable-length character encoding for Unicode. It is the preferred encoding for web pages.
Wesites using favicon rel tag
The http-equiv attribute provides an HTTP header for the information/value of the content attribute.
The http-equiv attribute can be used to simulate an HTTP response header.
Sites using Html 5 Audio Tag
Sites using Html 5 Embed Tag