Microcontent Notifications
MC Ping exists to enable the remixing of the web. It's a notification service that allows sites that post microcontent to notify other sites that might be interested in that content. Microcontent is a term used to describe small bits of content that are more structured than the typical web page or blog post. An example might be a review or event posting that contains additional markup to better describe the meaning of the post to another machine. Microcontent might be in the form of Microformats, it may be from the Structured Blogging system or it may come from a custom system.
The formats aren't important, it's the content that matters and the hope is that MC Ping enables substantial innovation in web based applications.