WorldCat Local (WCL) is a discovery service developed and maintained by OCLC and introduced around 2007. It provides access to more than 1.9 billion electronic, digital, and physical resources. In addition to indexing the contents of WorldCat, WCL also provides a central index that represents more than 2,200 e-content collections. A key, optional aspect to the service is a behind-the-scenes knowledgebase (KB) for managing those e-content collections. The KB is known as WorldShare Management Services Collection Manager, or WMS Collection Manager for short. WCL will eventually be replaced by a newer interface called WorldCat Discovery. Both interfaces draw upon the same data behind-the-scenes but provide very different user experiences.