Warning: mysqli_real_connect(): Headers and client library minor version mismatch. Headers:50549 Library:100121 in /var/www/html/wordpress/wp-includes/wp-db.php on line 1531 February 2016 - Taylor Lovett
http://notifyurl.com would be sent a notification HTTP request every time a post is created, updated, or deleted. All subscription routes, requests, and notifications are explained in detail on Github.
Using this plugin gives websites digesting your content an alternative to parsing feeds.