This article motivates testing as a way to facilitate the deployment of Large Scale Projects which have been launched to deliver online public services throughout Europe. Since these projects target heterogeneous communities in a cross-border context, their implementation effort is spread among different actors with diverse interests and capabilities. Test beds are required to ensure conformance to the common specification and interoperability between the implementations. This article demonstrates how the Global eBusiness Interoperability Test Bed (GITB) initiative addresses the requirements of these Large Scale Projects. The GITB Testing Framework specifies test artefacts, test components and test services to support the creation, use and operation of test beds while enabling reuse of testing resources among different test beds and regional communities.