DREB2005 will be held on the campus of Michigan State University, 22-25 June 2005. This will be the fourth of a series of workshops initialized by researchers from MSU, Florida, Saclay and Orsay. The earlier meetings were held in 1999 at Michigan State University (USA), in 2001 at IPN Orsay (France) and in 2003 at the University of Surrey (England). We intend to keep the informal character that has been a tradition with the DREB meetings, allowing for a low cost fee to attract many students. DREB aims at presenting the latest in the field and stimulating fruitful discussions. Thus the list of talks will be selected from the submitted abstracts only.