This document discusses interlibrary loan (ILL) systems and services used in the UK and Ireland. It provides an overview of the ILL options available in different library types and countries. It also describes recent developments to improve ILL functionality within the Koha integrated library system, including the addition of modular backends that allow Koha to connect to different ILL services and exchange requests via APIs or email. The document outlines the configuration and setup needed to enable and use Koha's ILL module with these backends.