Our goal is to allow end-user to easily create, visualize, analyze and share web
based thematics maps of its own arbitrary geographical business data.  In order to
achieve this, we developped a system centered on a XML description of data resources,
thematic maps contructions and representation options. 
This system provides the end user a set of nested base maps (e.g. city, districts,
regions boundaries), which are the foundation of the user defined thematic maps as
part of a join with user data.  Each registered user has its own data space in which
he can describe and upload data and construct thematic maps.  Technically speaking,
the XML resource representation is accessed by PHP routines and XSL stylesheets for
web pages construction,  Cartoweb+Mapserver configuration files and
PostgreSQL/PostGIS database queries. 

It is important to notice that the XML representation we developped for this
application is independant of implementation choices (Mapserver, PostgreSQL,
Cartoweb) and can be used as an API by any application to produce easy webmapping.