This document discusses social software and its application in libraries and cultural organizations. It defines social software as a range of software systems that allow users to interact and share data. The document outlines several types of social software including social networking sites, media sharing sites, virtual worlds, social bookmarking, wikis, blogs, and RSS feeds. It provides examples of how libraries currently use these tools and the opportunities they provide for user engagement and building communities. However, it also notes risks must be considered and addressed.