What is an integrated library system (ILS) and how do you choose one?

What an integrated library system does

An ILS centralizes four functions that libraries once ran separately: describing what is in the collection (cataloging), tracking who has borrowed what (circulation), deciding what to buy or subscribe to (acquisitions) and giving the public access to the catalog (the OPAC). It is also known as a library management system. The most widely used bibliographic description standard in these systems is MARC21, which keeps records compatible between libraries anywhere in the world.

"Integrated" is the key word. Because every module works on the same database, a record cataloged in the morning is searchable in the OPAC right away, a loan updates the item's availability for everyone, and an order placed in acquisitions becomes a catalog record without retyping. Libraries that keep cataloging in one tool, loans in a spreadsheet and the public catalog somewhere else pay for the gaps between them every day.

The modules of an integrated library system

Open-source vs proprietary ILS

The market splits into two models. Proprietary systems charge an annual license or subscription paid to the manufacturer, and the institution depends on that single vendor for upgrades and support. Open-source systems, such as Koha, have no license cost: the software is free, and what you pay for are implementation, migration, hosting and support services, which any integrator can provide.

Koha is one of the most widely used open-source ILSs, with installations in public, academic and special libraries around the world. It was born in New Zealand in 2000, and no company owns it: an international community governs the project through koha-community.org. Read what Koha is for its history and architecture.

Koha, Evergreen, FOLIO and proprietary systems compared

Beyond the open-versus-proprietary split, an institution evaluating options usually meets a handful of concrete names. The table below describes their models using what each project states about itself; it is a map, not a ranking.

Library services platform (LSP) is the term used for a newer generation of systems designed to manage print and electronic resources together. FOLIO describes itself as a collaboration of libraries, developers and vendors building an open-source LSP. For many public, school and academic libraries, a full ILS already covers the operational core; Koha, for example, has included an ERM module for electronic resources since version 22.11.

Questions to ask before choosing an ILS

• Can your current data be migrated? A system that does not cleanly import your existing catalog adds months of manual work. See how to migrate to Koha.
• Who controls your data if you change provider? In an open-source system, data is always exportable; with a proprietary one, check the contract.
• Is the public catalog (OPAC) customizable? Institutional identity matters for adoption by users.
• What does support include after go-live? Version upgrades, incident response times and who administers the server.
• Which standards does it support? MARC21, Z39.50 and SRU, SIP2 for self-check machines, OAI-PMH for harvesting and an API for integrations.
• Are upgrades included or charged each time? Some providers bill every upgrade separately.

Common mistakes when choosing an ILS

In the migration projects BiblioLabTech runs, the same mistakes repeat across different institutions. The most expensive is choosing the lowest license price without checking whether the system exports data in a standard format: if you later want to change provider and your records are trapped in a proprietary format, migration becomes a forced project instead of a free decision. The second is underestimating training: a new ILS run by a team that has not mastered its reports and circulation rules ends up used far below its capacity. The third is not asking about version upgrades: some providers charge for each one, which in the medium term can cost more than the initial project.

How to run an ILS selection

A structured selection avoids most of those mistakes. It does not need to be long, but it should follow this order:

1. Write down your requirements: number of branches, records, items and active patrons, circulation policies and the systems the ILS must talk to, such as authentication, self-check machines, the student information system or the repository.
2. Test with your own data. Ask each candidate to load a pilot batch of 200 to 1,000 of your real records, including difficult cases, instead of judging a demo built on the vendor's sample catalog.
3. Compare five-year costs, separating what is paid once (implementation, migration, training) from what is paid every year (license if any, hosting, support).
4. Check the exit before the entry: the contract should guarantee a full export of your records in MARC21 and of the database, with a deadline and no extra cost.
5. Decide the hosting and support model before signing, so the proposals you compare cover the same scope.

Cloud or on-premises ILS

An ILS can run on the institution's own server or on infrastructure managed by an external provider. Your own server gives full control but requires IT staff dedicated to maintaining it, applying security patches and responding if the server goes down on a weekend. The managed option moves that responsibility to the provider, with automatic backups and monitoring included. Neither is right universally: it depends on whether the institution already has IT staff dedicated to this kind of system or prefers someone else to do that work. For Koha specifically, see our guide to Koha hosting.

An ILS for libraries of any size

The same type of system works for a municipal public library with one service point and for a university network with several campuses and thousands of active users; what changes is the configuration, not the software. A school library usually needs simple circulation and a basic OPAC. An academic library needs acquisitions with budgets per faculty, multiple branches and statistical reports. A special library, such as a law, medical or research library, usually needs more granular cataloging and collections separated by material type. Koha supports all three profiles on the same platform: the difference lies in how it is configured at the start of the project, not in buying a different product for each size of institution.

ILS vs institutional repository

An ILS manages what the library lends; an institutional repository publishes what the institution produces in research. If your institution carries out its own research, they are complementary systems, not alternatives. The repository, typically DSpace, preserves theses, articles and datasets and exposes them to academic search engines through standards such as OAI-PMH. Read the full difference in our guide to the institutional repository.

How much an integrated library system costs

With Koha there is no license cost. What gets quoted are the services: implementation, migration from the previous system, hosting where applicable and ongoing support. As a reference, a single-campus university project with 15,000 to 25,000 records typically lands at USD 3,000 to 4,000 in the first year, depending on the volume to migrate. The full breakdown is in Koha implementation cost.

Upgrading an old ILS

It is not unusual to find libraries running Koha versions several years old, often because nobody dared to touch a system that "works" even though it no longer receives community support or security patches. Upgrading is not reinstalling from scratch: it means applying, in order, the database schema migrations accumulated since the current version, with a full backup first and a test environment to confirm nothing broke before touching production. The details are in how to upgrade Koha.

Koha with BiblioLabTech

BiblioLabTech implements, migrates, hosts and supports Koha-based integrated library systems for libraries in any country, including migrations from proprietary systems and from catalogs that were never automated. Every Koha implementation includes BiblioScan AI, our AI-assisted MARC21 cataloging tool, at no extra cost, to cut transcription work. The Escuela Colombiana de Ingeniería Julio Garavito runs its full catalog on Koha with BiblioScan AI cataloging; read the case study. To plan your project, see the Koha implementation guide and our Koha service, or contact us in English, Spanish, Portuguese or French.