This document discusses open source solutions that can be used to provide services to remote library users. It begins with an outline and definitions of open source software. It then discusses specific open source products that libraries commonly use, including content management systems like Drupal, Joomla and WordPress, as well as communication tools, media tools and library applications. Examples of library applications mentioned include the Blacklight OPAC. Throughout it addresses common concerns about open source software and provides statistics on open source use.