A conceptual framework, called the binding model, for the creation, deployment and management of multimedia services on ATM-based broadband networks with end-to-end quality-of-service (QoS) guarantees is presented. The key function of the associated binding architecture is to provide an open programmable environment that facilitates the easy creation of flexible services. We describe the implementation of a prototype binding architecture called xbind as a middleware toolkit for building open programmable ATM networks. Finally, we present our initial experiences with experimenting and deploying xbind over an ATM testbed and highlight some of the lessons learned.