DISQUS - Disqus is a global comment system that improves discussion on websites and connects conversations across the web.

Bumble - Bumble is a social network that allows you to feel empowered while you make those connections, whether you’re dating, looking for friends, or growing your professional network. One first move on Bumble could change your life.

Commento - A fast, bloat-free comments system to foster discussion on your website

Tinder - Tinder is how people meet. It's like real life, but better.

utterances - A lightweight comments widget built on GitHub issues.

Hinge - Find people you want to date through your friends on Facebook.