Social OPAC – SOPAC
John Blyberg is primarily responsible for the look and functionality behind the Ann Arbor District Library web site. Using Drupal as its base, he hooked into many additional services, e.g., tagging, reviews, ratings, and commenting — even within the III ILS. John has generously provided the source code. It works with III and Drupal and needs to be tweaked even if you use both, but even with that, much of the work has been done.
In his blog, John has provided a screencast of the features, as well as screenshots and the package for download.