In 2008 Elmo's interface saw some adjustments to enable more efficient access across HTTP. The challenge with this new interface is to understand how the object operations map to RDF operations and what implications they have on performance over http.
Despite the changes, EntityManager-oriented interface is still inappropriate for RDF/Object mapping, because relational operations do not directly map to RDF operations. Further, object persistence abstraction causes more performance problems then it solves for seasoned developers. Unlike object-relation mapping, RDF-object mapping is much more natural.
Work has already begun on Elmo's successor, AliBaba Object Repository, providing an hybrid RDF/Object interface extension to Sesame. Performance over HTTP is a high priority and was the major inspiration to the new interface.
Early development has already shown significant performance increases for both read heavy and write heavy transactions. For those interested in getting involved, you can checkout the code at