The goal of many FOSS4G deployments, and indeed development efforts, are the creation
of Spatial Data Infrastructures. SDIs are intended to be hierarchical - with activity
devolved down to the lowest level, and the "whole being greater than the sum of the
parts". In practive this is largely unrealised, and the tools are not yet good enough
to achieve it. This paper examines the fundamental requirements for SDIs to
interoperate, and focusses on the emerging methodologies for creating data standards
so that SDI components are worth connecting. Implemented examples using the Geoserver
platform will be provided, and an introduction will be provided to activities
developing data standards support within Geoserver and Geotools. Finally, a series of
guidelines and ideas for turning the "OpenSDI software stack" into a genuine SDI
toolkit will be explored, in advance of detailed requirements analysis to be expected
from an emerging alignment of global SDI architectures.