I’ve released Footnotes 1.0, a plugin for Habari that adds, well, footnote functionality. Right now it’s pretty basic (it works, is easy to style with CSS, and did I mention, works?), but I hope to expand the feature set in future releases.
Special thanks to the WP-Footnotes plugin which inspired the concept and some of the initial features.
Go to the Footnotes project page to download it now.