Conventional wiki software such as MediaWiki gives users one link to a "Talk" page per article. The comments therein can each refer to different sections of the article. This often results in a bit of a haphazard mess, in my experience.
I'm looking for a wiki that --ideally-- allows Reddit-style comment threads to be attached to any particle line of text in the article.
The comment trees could be located to the right side of the article and be minized (or truncated) by default, but expandable upon click or hover action.
A tall order perhaps, but does something like this exist?