Disqus is a networked community platform, reaching over 900 million people a month, 1.8 million registered communities, and over 300M active commenters. The service offers a networked comment system used to foster engagement and connect audiences from around the web. Disqus looks to make it very easy and rewarding for people ...
Open graph description entity tag
The Open Graph protocol enables any web page to become a rich object in a social graph, a open protocol supported by Facebook
Sites who has this tag are verfied by google to use WebMaster tools
A canonical link element is an HTML element that helps webmasters prevent duplicate content issues by specifying the "canonical", or "preferred".