After successfully testing Webmentions (a new form of the old Trackback or Pingback mechanisms), Jeremy Keith shows how to parse the content of the sites linking back to display excerpts of their comments:
The next step is to do something with the responses. After all, I’ve already got the source of each response from those cURL requests [to verify that the URL contains a back link as it claims]. […] I’m using [a microformats parser in PHP] to check the cURLed source for any responses that have been marked up using h-entry. That’s one of the microformats 2 vocabularies—a much simpler way of writing structured content with microformats.
This is a spec to watch as is everything from the Indie Web movement, because they make the web a better and more distributed place.