Borrow-Direct provides a single, searchable catalog of the combined holdings of the Brown, Columbia, Cornell, Dartmouth, University of Pennsylvania, Princeton, and Yale libraries.
The catalog software provides a web-interface, but no API, which prevents allowing this terrific resource to be incorporated into an automated borrowing system.
We at the Brown University Library have developed a Java API to Borrow-Direct that allows us to search and initiate requests to Borrow-Direct. The really nice thing about this API is that it works as a web-service, so regardless of what language you primarily code in, you can automate ISBN-based searching and requesting simply by calling this API via a url. We at the Brown Library have used this API with great success for over six months as part of our 'easyBorrow' system, documented at:
We intend to host this code at a Brown University Library Software subversion repository with anonymous checkout access, but while that is being set up we're offering it here.