K Koha Enterprise-class ILS with modules for acquisitions, circulation, cataloging, label printing, offline circulation for when Internet access is not available, and much more. Self-hostedOpen sourceDocument Management - Integrated Library Systems (ILS) 596GPL-3.0Perlupdated Oct 2026
E Evergreen Highly-scalable software for libraries that helps library patrons find library materials, and helps libraries manage, catalog, and circulate those materials. Self-hostedOpen sourceDocument Management - Integrated Library Systems (ILS) 157GPL-2.0PLpgSQLupdated Oct 2026
R RERO ILS Large-scale ILS that can be run as a service with consortial features, intended primarily for library networks. Includes most standard modules (circulation, acquisitions, cataloging,...) and a web-based public and professional interface. Self-hostedOpen sourceDocument Management - Integrated Library Systems (ILS) 87AGPL-3.0Pythonupdated Oct 2026