Koha is a free, open-source integrated library system (ILS) used by libraries worldwide to manage cataloging, circulation, patrons, acquisitions, serials and a public catalog. It is released under the GNU General Public License, so any library may download, run and modify it without paying a licence fee.
It is the most widely deployed open-source library system in the world, running in roughly 20,000 libraries — public, academic, school and special — from single-branch collections to national consortia.
This guide covers what Koha actually does, where it came from, who it suits, what it genuinely costs to run, and the three ways to get started.
What Koha does
Koha is a complete library system rather than a catalog with extras bolted on. Every module below ships in the same application and shares one database.
| Module | What it handles |
|---|---|
| Cataloging | Bibliographic records in MARC21 or UNIMARC, with frameworks, authorities and copy cataloging over Z39.50 and SRU |
| Circulation | Check-out, check-in, renewals, holds, transfers between branches, fines and overdues |
| Patrons | Member records, categories, permissions, messaging preferences and self-service accounts |
| OPAC | The public catalog patrons search, including holds, renewals, reading lists and reviews |
| Acquisitions | Suggestions, orders, vendors, budgets and fund accounting |
| Serials | Subscriptions, prediction patterns, issue receipt and claiming |
| Reports | Built-in statistics plus custom SQL reports |
| Administration | Branches, item types, circulation rules, authorized values and system preferences |
A short history
Koha was written in 1999 for the Horowhenua Library Trust in New Zealand, whose existing system would not survive the year 2000 rollover. It went live in January 2000 and was released as open source shortly afterwards — the first library system ever to be.
It is now maintained by an international community rather than a single company, on a scheduled release cycle with two major releases a year. No one vendor controls it, which is the practical reason a library cannot be held hostage over renewal pricing: support is a competitive market, and the software continues to exist regardless of who provides it.
Who uses Koha
- Public libraries — from single branches to city-wide systems with dozens of locations.
- Academic libraries — colleges and universities, including consortia sharing one union catalog across many campuses.
- School libraries — often the smallest deployments, and the ones most sensitive to who will maintain the system.
- Special libraries — law, medical, corporate, government and research collections.
The common thread is not size. It is that all of them wanted a full-featured system without a per-seat licence, and had some way to get it running and keep it running.
Koha’s core modules explained
Cataloging and MARC records
Koha stores bibliographic data as MARC records — MARC21 or UNIMARC, chosen when the system is installed and not changeable afterwards. It extracts a subset of those fields into ordinary database columns so that search and circulation can work quickly, which means catalogers need to understand which fields Koha actually reads.
Two fields matter more than the rest and are specific to Koha: 942 carries the item type and classification scheme, and 952 represents a physical copy — one 952 field per item on the shelf. A record with no 952 has no copies and will not appear as available in the catalog. Our guide to MARC21 in Koha covers both fields in detail.
Records do not have to be typed by hand. Koha can search remote catalogs over Z39.50 and SRU and import a matching record directly, which is how most libraries catalog most of their stock.
Circulation and patron management
Circulation is driven by rules rather than hard-coded behaviour. A circulation rule combines a patron category, an item type and a branch, and sets the loan period, renewal limit, hold policy, fine rate and more. This is powerful and is also where most configuration mistakes live — a rule that does not match anything means the default applies, silently.
The OPAC
The OPAC is the public face: search, availability, patron accounts, holds, renewals and reading lists. It is themable, and for many libraries it is the only part of the system the public ever sees.
Acquisitions and serials
Acquisitions covers the path from a purchase suggestion through an order to receipt and invoicing, with budgets and funds. Serials handles subscriptions and the prediction of when each issue should arrive, so missing issues can be claimed.
Reports and statistics
Koha ships with standard reports and a custom SQL report builder. The SQL builder is genuinely useful and genuinely dangerous: it runs against the live database, so a badly written report can be slow enough to affect the whole system.
Is Koha really free?
The software is free. Running it is not.
There is no licence fee, no per-seat cost and no renewal invoice. What a library still pays for is everything around the software:
- A server — bought or rented, sized for the collection, kept patched and online.
- Installation and configuration — the package install is the quick part; frameworks, circulation rules, patron categories and branches are the real work.
- Data migration — moving records, patrons, loans and history out of the previous system.
- Email that actually delivers — a mail server, SPF and DKIM records, and notice templates that somebody wrote and tested. Overdue notices silently landing in spam is one of the most common Koha complaints.
- Backups — automated, off-server, and restored at least once to prove they work.
- Upgrades — twice a year, tested before they touch the live system.
- Someone to call — when fines stop calculating and nobody knows why.
None of this is a criticism of Koha. It is simply what running any library system involves, and it is the part a licence fee would otherwise be paying for. A library with technical staff can absorb it. A library without them needs to plan for it before go-live, not after.
Koha compared with a proprietary ILS
Against commercial systems, Koha wins clearly on cost and on data ownership: there is no licence, and the database is yours in an open format you can export at any time. It is behind on electronic resource management, link resolution and out-of-the-box analytics, which is why large academic libraries often pair it with other tools. We compare it directly with Alma, Sierra, FOLIO and Evergreen elsewhere.
The honest summary is that Koha is an excellent library system whose deployment model — one install per library, maintained by that library — is what decides whether it works for you.
How to get started with Koha
There are three routes, and the right one depends far less on your collection size than on who will look after the system.
- Install it yourself. Free, and entirely reasonable if you have technical staff. Budget more time than the install guide suggests — the configuration, email setup and scheduled jobs take longer than the installation. Our breakdown of what installation actually costs sets out the real figures.
- Pay for implementation, then host it yourself. A specialist sets it up and hands it over. You own the server and everything that comes with it afterwards.
- Have it set up and hosted for you. Nothing to install and no server to run. The system is configured, the email and notice templates are already working, copy-cataloging sources are already connected, backups run daily and upgrades happen without a maintenance window you have to schedule.
The third route exists because the first two share one weakness: they both end with a library owning infrastructure it did not set out to own. If your staff would rather spend their time on students and the collection than on servers, that is a legitimate reason to choose it — and it is why we built a complete library system that is set up and hosted for you.
Frequently asked questions
Is Koha completely free?
The software is, under the GPL. Hosting, implementation, migration, training and support are not — those are real costs whoever provides them.
What database does Koha use?
MariaDB or MySQL, with Zebra or Elasticsearch providing the search index.
Does Koha support MARC21?
Yes, and UNIMARC. The format is chosen at installation and cannot be changed afterwards, so decide before you start.
Can Koha handle multiple branches?
Yes. Branches, per-branch circulation rules, holds with pickup locations and transfers between branches are all standard.
Who maintains Koha?
An international community of libraries, developers and support companies, on a published release schedule. No single vendor owns it.
How long does it take to get running?
A basic installation takes a few hours. A library actually going live — configured, data migrated, staff trained — is usually six to twelve weeks.
Thinking about Koha for your library? We install, migrate, host and support it — or set the whole thing up so you never touch a server. Tell us about your library and we will tell you honestly which route fits.