The Worldcat API was released beyond the original trial group while I was away.
The WorldCat Search API provides access to WorldCat bibliographic records and holdings using the FRBR concepts to pull together various editions of the same work. The API provides access to the WorldCat databases from clients that can send RESTful URI queries with either the OpenSearch or SRU protocols and can accept RSS, Atom, MARC XML or Dublin Core [WorldCat Search API [OCLC – Web and Data Services]]
