Evergreen ILS review: a free, open-source library system for cataloging, circulation and consortial sharing. See features, architecture, pricing and…
Evergreen is a free, open-source integrated library system (ILS) originally developed by the Georgia Public Library Service to run the PINES resource-sharing consortium, and it has since been adopted by public and academic library consortia around the world.
It handles the full range of core library operations, including cataloging (MARC21 bibliographic and authority records), circulation and holds, patron account management, acquisitions and serials, and a public search catalog, with an architecture designed to scale across large numbers of independently governed libraries sharing one system.
Evergreen is built on OpenSRF (Open Scalable Request Framework), a message-based service architecture backed by a PostgreSQL database, which lets a single installation scale to support hundreds of libraries and simultaneous users.
It supports standard library protocols including SIP2 for self-checkout hardware, Z39.50 and SRU for external cataloging and search, and MARC21 for bibliographic and authority records, alongside a web-based public catalog and staff client.
Evergreen itself is free: it is released under the GNU General Public License (GPL-2.0-or-later) and can be downloaded, self-hosted, and modified at no licensing cost.
Libraries that prefer not to self-host commonly contract with a support vendor such as Equinox Open Library Initiative for managed hosting, migration, and technical support, which is billed separately from the software itself since Evergreen has no vendor licensing fee.
Yes. Evergreen is released under the GNU General Public License (GPL-2.0-or-later), so it can be downloaded, self-hosted, and modified at no licensing cost. Libraries that want managed hosting and support typically pay a separate vendor, such as Equinox Open Library Initiative, for that service.
Evergreen is community-governed through an elected Evergreen Oversight Board made up of representatives from participating libraries, consortia, and service organizations. The project has been fiscally sponsored by the Software Freedom Conservancy since 2012 and has been transitioning toward operating as a stand-alone non-profit since 2019.
Evergreen uses PostgreSQL as its database, with business logic written primarily in Perl and performance-critical sections in C. It runs on OpenSRF, a message-based service middleware that lets Evergreen services scale across multiple servers.
Yes. It was originally built for the PINES consortium, a network of 252 Georgia public libraries sharing one catalog, and remains especially well-suited to statewide and regional consortia where many independently governed libraries need to share holdings and circulation.
Evergreen supports MARC21 for bibliographic and authority cataloging, SIP2 for self-checkout and self-service hardware integration, and Z39.50 and SRU for external search and copy cataloging.
Both are mature open-source integrated library systems. Koha generally runs on MySQL and is often considered easier to set up for a single library or small group, while Evergreen's PostgreSQL and OpenSRF architecture was purpose-built for large, complex multi-library consortial resource sharing at scale.