Library & Technology Glossary

Quick reference for terms used throughout the Unhinged Librarian site. Whether you're new to library technology, joining a board, or just need to clarify an acronym, this glossary is here to help.

A

API (Application Programming Interface)
A standardized set of rules and protocols that allow different software systems to communicate with each other and share data. In library context, APIs enable your ILS to talk to discovery layers, email systems, and third-party services without manual data entry. ↑ back to top

E

Embargo Window
A period, typically 6 months, during which libraries cannot lend newly purchased ebooks. Publishers impose this to protect hardcover sales. Libraries pay premium prices and get fewer checkout rights than they would for physical books. ↑ back to top
Enshittification
A pattern where digital platforms launch helpful and beneficial, then gradually squeeze users with restrictions, then extract maximum value before collapsing. Described by Cory Doctorow. Many vendor relationships follow this arc: free trial → moderate pricing → aggressive fees → exit costs. ↑ back to top
Evergreen
A free, open-source Integrated Library System built specifically for consortia (library groups sharing systems). Used by multi-library systems in Georgia, New Jersey, and Connecticut. More infrastructure overhead than Koha, but designed for shared governance from the start. ↑ back to top

I

ILS (Integrated Library System)
The core software managing a library's collections, patron records, circulation, and catalog. Every library depends on an ILS. Options range from proprietary systems (Alma, Sierra) costing $50K–120K annually to open-source alternatives like Koha or Evergreen (free or $3–5K/year). ↑ back to top

M

MARC (Machine-Readable Cataloging)
The international standard format for library metadata and catalog records. MARC records contain all details about a book (author, title, ISBN, subject headings) in a machine-readable format that every library system can understand and import/export. ↑ back to top
Metadata
Structured information that describes and organizes library resources. Includes title, author, ISBN, subject headings, publication date, and more. Good metadata makes discovery possible; poor metadata frustrates users and staff. ↑ back to top
MFA (Multi-Factor Authentication)
A security method that requires multiple forms of verification (password + phone code, password + fingerprint, etc.) to access systems. Blocks most ransomware attacks even if passwords are compromised. Often free through Gmail, Microsoft, or Okta. ↑ back to top

O

OCLC (Online Computer Library Center)
The organization managing WorldCat, the largest global library metadata database. Provides cataloging services, standards, and tools used by libraries worldwide. Maintains the Z39.50 protocol that enables searching across library systems. ↑ back to top

P

Patron Data
Information about library users including names, contact information, reading history, search patterns, and checkout records. Highly sensitive and protected by privacy laws. Vendors should be contractually prohibited from using it for AI training, analytics, or sale. ↑ back to top

R

RAG (Retrieval-Augmented Generation)
A technique where AI systems are fed curated sources (library collections, verified databases) instead of relying on general training data. More reliable than generic AI because it retrieves factual information before generating answers. Growing tool for library research assistance. ↑ back to top

S

SLA (Service Level Agreement)
A contract clause specifying uptime guarantees, support response times, and penalties for vendor failures. Example: "System uptime 99.9% or vendor provides service credit." Binding and enforceable. Should be a standard part of every vendor contract. ↑ back to top

V

Vendor Lock-in
Situation where a library cannot easily switch vendors due to export restrictions, proprietary data formats, high exit costs, or incomplete documentation. Creates negotiating leverage for vendors and reduces library independence. Open-source systems like Koha minimize lock-in. ↑ back to top
VPN (Virtual Private Network)
A secure, encrypted connection that allows remote access to library systems. Essential for staff accessing sensitive patron data from home or during travel. Should be required for any remote access to administrative systems. ↑ back to top

Open Source Library Systems

Koha
A free, open-source Integrated Library System used successfully by hundreds of small public and academic libraries worldwide. No licensing fees; hosting costs $3–5K/year from managed providers like Bywater Solutions or Equinox. Active community support. Requires some technical capability but saves $35–40K/year compared to proprietary systems. ↑ back to top
Discovery Layer
A modern search interface (like VuFind) that sits between patrons and the library catalog, providing Google-like search experience with faceted results. Intended to improve discoverability but effectiveness depends on implementation quality and collection metadata. ROI often lower than expected. ↑ back to top