The eXtensible Catalog (XC) Project is working to design and develop a set of open-source applications that will provide libraries with an alternative way to reveal their collections to library users. XC will provide easy access to all resources (both digital and physical collections) across a variety of databases, metadata schemas and standards, and will enable library content to be revealed through other services that libraries may already be using, such as content management systems and learning management systems. XC will also make library collections more web-accessible by revealing them through web search engines.Since XC software will be open source, it will be available for download at no cost. Libraries will be able to adopt, customize and extend the software to meet local needs. In addition, a not-for-profit organization will be formed to provide the infrastructure to incorporate community contributions to the code base, encourage collaboration, and provide maintenance and upgrades.