The Distributed Resource Controller (DRC) technology described in this paper provides a novel approach to interfacing applications with emerging network mechanisms to deliver Quality of Service (QoS) and controlling network resource utilization. DRC aims to unify network services (e.g., Diffserv, Intserv, and ATM) and application QoS provisioning by introducing a middleware system and a set of generic interfaces. DRC middleware is the core part that translates application requests for QoS delivery into respective access to underlying network systems in a manner that optimizes resource utilization and shelters applications from such a complexity. Applications can request QoS to the DRC middleware in two ways: either in-line using the DRC QoS API or off-line via the DRC utility. Application QoS requirements are specified in terms of two categories of parameters: Traffic Profile (quantitative) and User Expectation (qualitative). DRC currently uses the CORBA-based object-oriented technolo...