The paper entitled "What is a good digital library?" - A quality model for digital libraries is number one in the list of Top 25 hottest articles in "Information Processing and Management." Drs. Marcos Andre Goncalves and Barbara Moreira (Computer Science department, Federal University of Minas Gerais, Brazil) and Drs. Edward A. Fox and Layne T. Watson (Computer Science department, Virginia Tech) elaborate on the meaning of quality in digital libraries by proposing a model grounded in a formal framework for digital libraries, the 5S (Streams, Structures, Spaces, Scenarios, and Societies.)