In addition to providing access to its own software, a repository may wish to import software descriptions from other repositories and make this software available from its own interface. For example, a computational chemistry repository may wish to provide access to mathematical software and to parallel processing tools in a manner tuned to the computational chemistry discipline. A repository interoperation architecture is shown in Figure 1.
Figure 1: Repository Interoperation Architecture
The NHSE is using the Reuse Library Interoperability Group's Basic Interoperability Data Model (BIDM) as its interoperability mechanism [&make_named_href('', "node19.html#Browne-repointerop","[4]")]. Participating HPCC repositories and some individual contributors have placed META and LINK tags in the headers of HTML files that describe their software resources. This information may then be picked up by other repositories and incorporated into their own software catalogs. The NHSE is developing a toolkit called Repository in a Box (RIB) that will assist repository maintainers in creating and maintaining software catalog records, in exchanging these records with other repositories (including the top-level virtual NHSE repository), and in providing a user interface to their software catalog. The Resource Cataloging and Distribution System under development at the University of Tennessee will provide a scalable substrate for repository interoperability by providing catalog and location servers that map resource names to catalog and location information.