The Digital Historical Atlas of South India is a desktop/web-based application. It has been prepared using the latest Geographic Information Systems (GIS) technology. Its geographical coverage includes entire states of Tamil Nadu and Kerala and two pilot areas in the states of Andhra Pradesh and Karnataka. It covers vast time range from prehistoric times to AD 1600 organized into seven major periods and under four major themes. Altogether, there are at present 7000 sites of archaeological and historical importance put on the maps with all the related theme-based information. Facilities are provided to navigate through, and interact with, by querying, the entire database by time, space, and themes. Maps have been illustrated by three different versions, namely Scalable Vector Graphics (SVG) version, Google Earth version and Map Server version, the last one being in the experimental stage.