Doing a demo of POSSE and Webmentions at the Pasadena WordPress Developer Meetup.

Here are some resources for those attending:

Webmention recommended spec at the W3C

Webmention page at Indieweb.org

Getting started with Indieweb on WordPress instructions

Webmention plugin for WordPress

Semantic Linkbacks plugin for WordPress

Syndication Links plugin for WordPress

Brid.gy

Code for auto-accepting webmentions