Pleiades: Building a RESTful, Open Source GIS for the Humanities
Presentation | Presented
- Sean Gillies, Ancient World Mapping Center, University of North Carolina at Chapel Hill
Pleiades is an online workspace for ancient geography. It brings together a global community of scholars, students and enthusiasts to expand and enhance a a 50,000+ feature dataset for Greek and Roman history, originally assembled by the Classical Atlas Project (1988-2000) to support the publication of the Barrington Atlas of the Greek and Roman World (R.J.A. Talbert, ed., Princeton, 2000). Combining community approaches (like those used by Wikipedia) with academic-style editorial review, Pleiades enables anyone -- from university professors to casual students of antiquity -- to suggest updates to geographic names, descriptive essays, bibliographic references and geographic coordinates. Once vetted for accuracy and pertinence, these suggestions become a permanent, author-attributed part of future publications and data services.
Pleiades is entirely open source and based on the Linux/Apache/PostgreSQL/Python stack. It is a software product as well as a workspace, a product readily repurposed by other scholarly, environmental, or special interest communities. Development of Pleiades has already fed back into the open source GIS world with enhancements to the Python Cartographic Library, and OpenLayers, and creation of the OWSLib and Quadtree packages for Python. Pleiades has contributed bug fixes to the Plone Collective, and has also produced two packages that are finding use in the Plone community.
Pleiades is designed to interoperate with traditional GIS applications via WMS and WFS protocols, but is primarily a Web GIS, and a data source for revolutionary mashups across the range of humanities and heritage resource web computing. Intuitive features for content creation and simple mechanisms for interoperability receive equal focus in development. Both priorities rely upon our object-oriented data model, which treats spatial and attribute data even-handedly. As a result, Pleiades is flexible enough to manage the complex relationships between measured (and estimated) locations, names attested in historical sources and the types of uncertainty inherent in any complex study of the past.
This talk will describe the development infrastructure and methodology of Pleiades, the LAPP stack, and how the package can be adapted to new open source projects. Special attention will be paid to the REST architecture of Pleiades and the role of resources in a RESTful Web GIS. The discussion will be built around practical how-tos, including:
* designing and maintaining permanent, cool URLs for geospatial resources
* leveraging HTTP caching with Last-Modified headers and ETags
* using emerging standard geospatial representations such as GeoRSS, GML, and KML
All of these topics are increasingly important to the Web-scale practice of open source GIS.
Pleiades is organized by the Ancient World Mapping Center at the University of North Carolina at Chapel Hill, U.S.A., and hosted by the Stoa Consortium at the University of Kentucky. Initial startup funding for Pleiades is generously provided by the U.S. National Endowment for the Humanities with a two-year grant (2006-2008) through its Preservation and Access Research and Development program.