Developed a geospatial overlay enhancement for the schism-dev/schism repository, delivering direct ESRI shapefile visualization within the xmgredit5 grid editor. The work involved implementing a self-contained shapefile reader in C, supporting multiple geometry types and eliminating reliance on external libraries to streamline deployment and maintenance. Integrated the new functionality into the user interface with a dedicated dialog and menu option, updating the drawing loop to render overlays aligned with world coordinates for seamless pan and zoom. This feature enables users to visualize GIS data directly in the editor, leveraging C programming, geospatial data handling, and UI development skills throughout the process.