Handle System

The Handle System is a proprietary registry assigning persistent identifiers, or handles, to information resources, and for resolving "those handles into the information necessary to locate, access, and otherwise make use of the resources".^[1] As with handles used elsewhere in computing, Handle System handles are opaque, and encode no information about the underlying resource, being bound only to metadata regarding the resource. Consequently, the handles are not rendered invalid by changes to the metadata.

The system was developed by Bob Kahn at the Corporation for National Research Initiatives (CNRI) as a part of the Digital Object Architecture (DOA). The original work was funded by the Defense Advanced Research Projects Agency (DARPA) between 1992 and 1996, as part of a wider framework for distributed digital object services,^[2] and was thus contemporaneous with the early deployment of the World Wide Web, with similar goals.

The Handle System was first implemented in autumn 1994, and was administered and operated by CNRI until December 2015, when a new "multi-primary administrator" (MPA) mode of operation was introduced. The DONA Foundation^[3] now administers the system's Global Handle Registry and accredits MPAs, including CNRI and the International DOI Foundation.^[4] The system currently provides the underlying infrastructure for such handle-based systems as Digital Object Identifiers (DOI) and DSpace, which are mainly used to provide access to scholarly, professional and government documents and other information resources.

CNRI provides specifications and the source code for reference implementations for the servers and protocols used in the system under a royalty-free "Public License", similar to an open source license.^[5] Thousands of handle services are currently running. Over 1000 of these are at universities and libraries, but they are also in operation at national laboratories, research groups, government agencies, and commercial enterprises, receiving over 200 million resolution requests per month.^{[citation needed]}