Koha - Koha is the first free and open source software library automation package (ILS).
Greenstone Digital Library - Greenstone is a suite of software tools for building and distributing digital library collections...
Evergreen ILS - Evergreen - Open Source Library Software
TinyCat - The online catalog and integrated library system for tiny libraries, powered by LibraryThing.
Atoll Digital Library - Atoll Digital Library is an open source platform for building digital library collections.
Omeka - Omeka is a free, flexible, and open source web-publishing platform for the display of library, museum, archives, and scholarly collections and exhibitions.