The spatial dimension and geographic variation of poverty has been the subject of great scholarly debate among policy-makers and academics for numerous decades. Some have commented that dense concentrations of underclass persons create a "culture of poverty," while others lay the blame on architects, urban planners, and a host of others. This engaging and useful site is a product of the Bruton Center at the University of Texas at Dallas under the direction of Professor Paul Jargowsky. The Windows on Urban Poverty project Web site contains a research paper on the changes in the concentration of poverty between 1990 and 2000 (also released as a publication through the Brookings Institution) and a mapping tool that lets visitors view the relative concentrations of poverty in cities around the United States. There is a small section that introduces users to the process of using the mapping tool, which will be quite helpful to those unfamiliar with utilizing maps in this fashion (Users should note that the interactive mapping tool on the site is only supported by Internet Explorer).