TinyCat - The online catalog and integrated library system for tiny libraries, powered by LibraryThing.
Sierra ILS - Sierra is designed to make your library effective.
Koha - Koha is the first free and open source software library automation package (ILS).
LibraryWorld - Library automation solution
DSpace - DSpace open source software enables open sharing of content that spans organizations, continents...
Alma - Meet Alma, a modern and affordable integrated student information system (SIS) and learning...