Scriblio (formerly WPopac) is an award winning, free, open source CMS and OPAC with faceted searching and browsing features based on WordPress. Scriblio is a project of Plymouth State University, supported in part by the Andrew W. Mellon Foundation.
eXtensible Catalog is open source, user-centered, next generation software for libraries. It comprises four software components that can be used independently to address a particular need or combined to provide an end-to-end discovery system to connect library users with resources.
Open source Full-featured ILS. In use worldwide in libraries of all sizes, Koha is a true enterprise-class ILS with comprehensive functionality including basic or advanced options. Koha includes modules for circulation, cataloging, acquisitions, serials, reserves, patron management, branch relationships, and more. linux and perl.
highly-scalable software for libraries that helps library patrons find library materials, and helps libraries manage, catalog, and circulate those materials, no matter how large or complex the libraries. windows.