For now this question will serve as a "living document" of all features.

Comments are plain text but support Markdown as a power up.

A Namespace owner can moderate comments. They can edit or delete any comment as if they wrote it.

For details, checkout: What is a Namespace?

Control how Remarkbox looks on your site with a custom stylesheet.

Default avatars and optionally Gravatar.

Deeply nested comments

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Works anywhere that supports HTML!

Comments help your page SEO and search.

Comments are plain text but support MathJax as a power up for Mathematical equations.

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All of your comments for all of your web sites from a single dashboard!