CIVICgov - Gov Tech
DISQUS - Disqus is a global comment system that improves discussion on websites and connects conversations across the web.
Intelligov - Gov Tech
IntenseDebate - IntenseDebate's comment system enhances and encourages conversation on your blog or website.
eMunicipality - Gov Tech
Commentbox - Commentbox is a jsf component that allows quick realization of a comment functionality