The Live Access Server (LAS) is a general purpose Web-server for geo-science data sets. Data providers can use the three tiered LAS architecture to build custom Web interfaces to their scientific data. Users can then access the LAS site to search the provider’s on-line data holdings, make plots of data, create sub-sets in a variety of formats, compare data sets and perform analysis on the data.

The Extensible Markup Language (XML) has been a part of the LAS design and implementation for much of the history of the product. Early on LAS was able to take advantage of the flexibility and ease of implementation that comes with using XML and to use some the myriad of tools available for XML manipulation.

That said, just as LAS has not stood still with many new and innovative features being added with each release, XML has advanced as well. Part of the recent advances in XML have to do with schema languages used to define the contents of XML documents. The LAS team has decided that it is important to take advantage of these new tools and to undertake a redesign of the XML used to configure LAS.

This paper will explore the process of redesigning the LAS XML. It will give a complete technical description of the final schema for LAS configuration. It will offer many insights in to the process of choosing an XML schema language and designing a schema that is both easy to use and flexible enough to handle the complex needs of LAS configuration.