DISQUS - Disqus is a global comment system that improves discussion on websites and connects conversations across the web.
Ziflow - Online Proofing software from Ziflow keeps teams connected and collaborating by providing a single source of truth for creative review and approval.
Hyvor Talk - The Best Commenting Platform For Your Website
GoVisually - GoVisually empowers creative teams to deliver better designs, by providing a simple way to review and approve designs quickly and easily
Commento - A fast, bloat-free comments system to foster discussion on your website
PageProof - Online proofing of anything and everything, made simple. Streamline feedback for easy collaboration, secure workflows, and faster approvals. PageProof. The smarter way to review.