<p>Blacklight is an open source Ruby on Rails gem that provides a discovery interface for any Solr index. Blacklight provides a default user interface which is customizable via the standard Rails (templating) mechanisms. Blacklight accommodates heterogeneous data, allowing different information displays for different types of objects and features faceted browsing, relevance based searching, bookmarkable items, permanent URLs for every item, and user tagging of items.</p>