The Digital Library Federation has released DLF ILS Discovery Interface Task Group (ILS-DI) Technical Recommendation: An API for Effective Interoperation between Integrated Library Systems and External Discovery Applications.
Here's an excerpt from the announcement:
This document recommends standard interfaces for integrating the data and services of the Integrated Library System (ILS) with new applications supporting user discovery. Such standard interfaces will allow libraries to deploy new discovery services to meet ever-growing user expectations in the Web 2.0 era, take full advantage of advanced ILS data management and services, and encourage a strong, innovative community and marketplace in next-generation library management and discovery applications.
A group of eight professionals from major North American research libraries prepared the recommendation during late 2007 and early 2008. Members of the group surveyed the library community about their needs, made presentations, and held open discussions face to face and online with librarians, developers, and vendors. The group made multiple recommendation drafts and other background information publicly available on the task group's Wiki, and invited comments and suggestions from interested parties.
In March, the DLF convened a meeting that brought together Task Group members and representatives of library system vendors and developers, and produced the "Berkeley Accord", an agreement about the most essential and feasible interfaces to include in an initial set of interfaces. This set of interfaces, called the "Basic Discovery Interfaces", is described in detail in the new ILS-DI recommendation. The recommendation also describes and recommends a variety of other functions to support higher levels of interoperability.