I've noticed an uptick in the buzz on webmentions recently. According to the W3C page, a Webmention is "a simple way to notify any URL when you mention it on your site. From the receiver's perspective, it's a way to request notifications when other sites mention it." But from the Indieweb perspective, it "is a web standard for mentions and conversations across the web, a powerful building block that is used for a growing federated network of comments, likes, reposts, and other rich interactions across the decentralized social web." The discussion on A List Apart provides a good technical overview. Here's more from Chris Aldrich.