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.
Polyfill is a service which accepts a request for a set of browser features and returns only the polyfills that are needed by the requesting browser.
This site uses the viewport meta tag which means the content may be optimized for mobile content.
Network infrastructure from Active 24 based in the Czech Republic.
The BIG-IP product suite is a system of application delivery services that work together on the same best-in-class hardware platform or software virtual instance. From load balancing and service offloading to acceleration and security, the BIG-IP system ensures your applications are fast, secure, and available.
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.
Content Security Policy is best used as defense-in-depth, to reduce the harm caused by content injection attacks.
Chrome for Android, since version 39 supports the "theme-color" meta tag to allow websites control the background color of the tab's UI header.
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.
Sites who has this tag are verfied by google to use WebMaster tools
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.
UTF-8 (8-bit UCS/Unicode Transformation Format) is a variable-length character encoding for Unicode. It is the preferred encoding for web pages.