Invenio - Invenio is a free, open-source software to run a digital library or document repository on the web.
Evergreen ILS - Evergreen - Open Source Library Software
Greenstone Digital Library - Greenstone is a suite of software tools for building and distributing digital library collections...
TinyCat - The online catalog and integrated library system for tiny libraries, powered by LibraryThing.
Koha - Koha is the first free and open source software library automation package (ILS).
VuFind - VuFind is a library resource portal designed and developed for libraries by libraries.