Open Graph Protocol
13,307,439 websites

Open Graph Protocol is free to use

http://ogp.me

The Open Graph protocol enables any web page to become a rich object in a social graph, a open protocol supported by Facebook

VS

X-UA-Compatible
11,141,235 websites

X-UA-Compatible is free to use

http://blogs.msdn.com/ie/archive/2008/06/10/introducing-ie-emulateie7.aspx

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.

Market Share by Top Websites

1 Open Graph Protocol is leading in Top 10K Sites, Top 100K Sites, Top 1M Sites and The Entire Web.

2 In terms of market share, X-UA-Compatible is clearly lagging behind, losing to Open Graph Protocol in all segments.

Websites Categories

1 Open Graph Protocol has better usage coverage in more websites categories. Including Computers Electronics & Technology, Arts & Entertainment, Science & Education, Games and 18 other categories.

2 X-UA-Compatible is leading in Finance and Law & Government.

Geography

1 Open Graph Protocol is leading in most countries, including United States, Japan, Germany, United Kingdom and 158 other countries.

2 X-UA-Compatible is leading in China, South Korea, Hong Kong and Macao.