The Webmention specification is used to enable cross-site commenting and reactions between independent websites. The specification reached Candidate Recommendation in May 2016, and was promoted to Recommendation in January 2017.
Private Webmention is an extension that supports sending and verifying Webmentions for posts that require access control.
webmention.rocks is a test suite you can use to test your Webmention implementation.
Micropub is an open API standard used to create posts on one's own domain using third-party clients. Web apps and native apps can use Micropub to post short notes, photos, events or other posts to your own site.
The specification reached Candidate Recommendation in August 2016, and was promoted to Recommendation in May 2017.
micropub.rocks is a test suite you can use to test your Micropub implementation.
In 2016, the W3C adopted PubSubHubbub into the working group, and renamed it to WebSub. I've written a simplified guide to WebSub, as well as the test suite and validator, websub.rocks. In November I was added as a co-editor of the spec.
In January 2018, WebSub was published as a W3C Recommendation!