This sure is exciting news: the various groups that make up the W3C have agreed upon a set of rules by which we’ll be able to annotate, highlight and make comments to a webpage without the need of a third party script or framework.
Dan Whaley describes why this could be a big deal:
The W3C standards are a key milestone towards a future in which all pages could support rich layers of conversation without requiring any action by their publishers—because that capability can be built into the browser itself and be available as a native feature, just like like web search. The shared vision is that conversations will be able happen anywhere on the Web, or even on documents in native apps, and inline instead of below-the fold, in a federated, standards-based way.