This document discusses the transition from traditional "Web 1.0" libraries to more modern "Library 2.0" principles in the digital environment. Library 2.0 utilizes new Web 2.0 tools that enable dynamic, frequently updated content, active user participation, collaboration and user-generated content. Key aspects of Library 2.0 include blogging, wikis, podcasting, communities, tagging and more. The principles seek to make libraries more user-centered and encourage participation through open access and new communication technologies. Examples are given of libraries that have adopted Library 2.0 approaches and tools.