Google+ platform websites integration using the Google+ platform tag.
The Tweet Button is a small widget which allows visitors to share content and connect on Twitter.
Let visitors recommend your content on Google Search and share it on Google+.
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.
Open graph description entity 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.