TimeMap is an innovative project combining technologies from geographic information science and digital library research. It allows diverse digital resources on servers around the world to be combined and viewed on a single map interface. It is also a way to generate interactive maps that show change over time. TimeMap allows users to select digital resources with information about time and space in order to create customized maps based on their interests. While digital resources are catalogued in a central clearinghouse, the data itself may be located anywhere in the world.

TimeMap allows users to find resources, frame questions, and organize materials spatially, and test hypotheses about events in time and space.

• Space: Users can explore a region of any size, from the entire world to a single building, and find appropriate data at any scale.
• Time: TimeMap can show change over time, so users can track transportation in the last week, or observe the spread of a religion throughout the world over many centuries.
• Content: Items on the maps can be linked to non-spatial resources: photographs, sound files, videos, texts, or tables, and in that way, the map can be a portal into a world of digital data. A TimeMap project can include georeferenced aerial photographs or scanned paper maps as well as points, lines or polygons.
• Expansion: While the datasets accessed through TimeMap are located all over the world, they can be easily found and integrated through a centralized web-based clearinghouse. This means that accessible data about time and place, like any library's collection, can be expanded as knowledge develops.

TimeMap includes tools and applications that allow various functions.

• Indexing, searching and accessing datasets: TimeMap supports mapping as well as discovery of resources. In addition to bibliographical information, specially customized TimeMap metadata describes network connection protocols and structural features of datasets. This metadata allows retrieval of spatial and temporal information and associated attributes for display on a map interface.
• Creating and viewing interactive maps. TimeMap's browser-based map interface, TMJava, allows users to browse resources in the clearinghouse, create dynamic maps from selected datasets, and navigate from the map to associated web resources. With the enhanced map interface and map authoring tool — TMView — users can gather datasets drawn from the clearinghouse and locally stored files onto a single map, filter them according to time and space, and produce customized cartography. User-authored maps can be added back into the clearinghouse to be shared with others.
• Data editing and metadata creation. TimeMap also includes tools to assist people who wish to create datasets compatible with TimeMap and use them locally or register them in the clearinghouse. These include a metadata editor (TMEdit), and a map geo-registration tool (TMGeoReg).

TimeMap is being developed by the Archaeological Computing Laboratory at the University of Sydney. For more information about TimeMap, visit www.timemap.net.