FRBR News and Prototype Catalogue
The interface simply presents the user with search options based on the primary FRBR entities and the database is very small, but it demonstrates the principles and models the relations between all the entities.
A preprint version of a technical paper is available; it's published in Cataloguing & Classification Quarterly vol. 39 no. 3-4 2004. This is devoted to FRBR and edited by Patrick Le Bœuf of the Bibliothèque nationale de France, who is at the hub of IFLA's work on FRBR. The title of the CCQ double issue is FRBR: hype, or cure-all? There has certainly been a lot of hype about it and Patrick is the first to point out that it is an imperfect conceptual model, but it does seem to offer possibilities to improve the performance of catalogues for key types of material such as literary works and music to better fulfil Cutter's principles.
Scanning the contents list for CCQ 39, 3-4, there are many fascinating articles that I look forward to reading from key players in cataloguing research, but there doesn't seem to be a user study. Given the well-documented user preference for Google's simplicity, I would have thought that those who are investing in the application of FRBR concepts would want to know whether their systems are going to appeal to their intended user-base and how best to design their user interfaces to do so.