Now you can manage your posts and comments remotely, without signing in to the admin area directly, using Atom Publishing Protocol or AtomPub.
AtomPub is another option to allow you can now log in to your blog with an AtomPub-enabled client and publish, update and delete posts and media files remotely, without needing to log in to the administration section directly.
While remote posting has been possible using a number of protocols, AtomPub is a well defined protocol that should promote interoperability.
WordPress’s AtomPub service address is http://[Blog URL]/wp-app.php/service. Your AtomPub client should be configured to point to that address.