What started as a small, simple specification ended up spread over 5 (and counting) documents. Given that these are still moving targets, at least for a little bit longer, it can get very confusing for people trying to follow this work. A few months ago I wrote about the new discovery stack which included XRD, LRDD, and the three links. Since then, the design has changed to include new components and some shuffling of the existing ones.
The main components remain XRD, host-meta, and LRDD. They are slightly rearranged to move XRD lower in the protocol stack, as it no longer provides its own discovery flow, only a simply schema to describe resources. host-meta has been redefined and /.well-known added for the more generic use cases. And last, WebFinger was added to present a more comprehensive picture of the discovery framework being discussed.
In addition, the latest draft of Web Linking removed the need to list the individual link locations (e.g. HTTP header, <Link> elements in HTML and ATOM). Web Linking is in its final standardization phase and will be covered by an upcoming post.
I am also working on reworking LRDD from a generic guide on linking to metadata, to a more restrictive protocol on finding specific links using linked XRDs and direct links. Stay tuned.