The Web-based Disease Mapping and Analysis Program (WebDMAP) is a web-based Geographic Information System (GIS) software designed to generate smoothed, continuous maps of crude or age-adjusted disease rates. WebDMAP provides advanced spatial analysis, GIS, and visualization methods in an easy-to-use, web-based analysis system designed specifically for users with little experience in spatial analysis methods or GIS software. WebDMAP is built using free, open-source products and is available as free, open-source software. Please check the wiki page for more details and latest updates.
Update (August 28, 2016): A new Java-based version is ready for beta-testing. It runs on Windows, Mac, and Linux. The software requires PostgreSQL_PostGIS. If a local database server is not available, the software provides a built-in interface for provisioning a database instance using Amazon Web Services (AWS). Once your analysis is complete, you can choose to delete the cloud instance of PostgreSQL. For more information on the beta version contact Chetan Tiwari here.
The Suppression Toolkit allows users to compute directly age-adjusted rates using suppressed case data obtained from CDC WONDER. Due to data privacy and confidentiality concerns, CDC WONDER suppresses data cells that contain less than 10 case counts. Directly age-adjusted rates computed from such data can result in an underestimation of true rates. This toolkit substitutes expected case counts for all suppressed data cells based on some regional risk (such as statewide rates), thus removing any underestimation biases caused due to suppression. Download from here.