Designed a custom web service to deliver real property assessment data and display tiled geographic tax maps. To create this system several software design processes were employed including use case analysis, interaction diagrams, entity relationship models, and database normalization. The system was created with CodeIgniter, an open-source rapid development web framework for building dynamic web sites with PHP. Access control and user administration was achieved by integrating a third-party user authentication system into the framework. Using OpenLayers, an open source dynamic mapping client, system users can view 25,000 tax maps rendered from over 60 million individual image tiles.