DISQUS - Disqus is a global comment system that improves discussion on websites and connects conversations across the web.
Joint Comments - An embeddable comment widget for websites, blogs, ecommerce & static pages.
HashOver - HashOver is a PHP comment system intended as a replacement for services like Disqus.
Hyvor - Hyvor is a privacy-focused and fully-featured commenting system created for almost all kinds of web applications and blogs.
talkatv - talkatv is an open source comment service much like ...
Hyvor Talk - The Best Commenting Platform For Your Website