This script is the defacto way to enable use of HTML5 sectioning elements in legacy Internet Explorer.
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
A canonical link element is an HTML element that helps webmasters prevent duplicate content issues by specifying the "canonical", or "preferred".
A scheme.org entity that represents an organization such as a school, NGO, corporation, club, etc.