WorldCat is the world´s largest network of library content. It lists about 1.5 billion records from over 10,000 libraries worldwide. After performing a search and displaying the results in a uniform way you can directly link into the local library catalogues. Additionally social web functionality can be used for e.g. creating lists, bibliographies and reviews.
For a short time the collections of the university library of Bayreuth are included in WorldCat - as well as the collections of all university and state libraries in Bavaria.