Automattic

John Godley

Donncha O Caoimh (a11n)

Eoin Gallagher

Lenny

Future upgrades to Sharedaddy plugin will only be available in <a href="http://jetpack.me/" rel="nofollow ugc">Jetpack</a>.
Jetpack connects your blog to the WordPress.com cloud, <a href="http://jetpack.me/support/" rel="nofollow ugc">enabling awesome features</a>.

Sharedaddy

Future upgrades to Sharedaddy plugin will only be available in Jetpack.

Mirco Babini

LinkedIn Perfect Share detects when LinkedIn is parsing/crawling the Open Graph tags of a post/page and provides a simplified version of the contents. This allows the scraper to see the correct sharing post’s data for the provided URL; the information includes the post title, the description and the Featured Image (that is the standard content for the WordPress’ og:image field).
Full description here: http://www.mircobabini.com/project/linkedin-perfect-share-plugin-for-wordpress/ 
Developed by Mirco Babini, WordPress Consultant, Web Developer and Data Lover.
<h4>Usage</h4>
It just works. You simply need to install and activate it.

LinkedIn Perfect Share

Provides precise Open Graph data to LinkedIn for perfect sharing

Sharedaddy vs LinkedIn Perfect Share