Websites using some form of Captcha technology on them.
Anti-bot CAPTCHA widget that helps digitize books by providing snippets of books for people to enter the text for. Owned by Google.
CloudFlare is a global CDN and DNS provider that can speed up and protect any site online.
This site uses the viewport meta tag which means the content may be optimized for mobile content.
nginx [engine x] is a HTTP server and mail proxy server written by Igor Sysoev.
Meta descriptions are HTML attributes that provide concise explanations of the contents of web pages. Meta descriptions are commonly used on search engine result pages (SERPs) to display preview snippets for a given page.