The DSpace 4.0 Release Candidate 2 is out, it was released not so long ago.

The features of this release are:-

• New look and feel for JSPUI, with several other improvements
• A number of features of XMLUI have been ported to JSPUI
• REST API exposing repository objects
• Support for automatically creating DOIs during ingestion

Read about this release here.

Why not try it , find the files here.