Webmention.io - Webmention.io is a hosted service created to easily receive webmentions on any web page.
Bridgy - Bridgy pulls comments, likes, and reshares on social networks back to your web site. You can also use it to post to social networks - or comment, like, reshare, or even RSVP - from your own web site. https://brid.gy/
Blog2Social - Auto post, cross post, re publish, re post and schedule your WordPress blogs posts to social networks like Facebook, Twitter, LinkedIn, Instagram, Pinterest
Scuttlebot - A peer-to-peer log store
Scuttlebutt - A decent(ralised) secure gossip platform.
Diaspora - The online social world where you are in control.