We have witnessed the emergence of different types of multimedia applications particularly those involving continuous media such as digital audio and video. Improvements in hardware, software, and networking technologies are enabling wide deployment of these applications each with its own quality of service (QoS) requirements. Along with these technological advances, Java has emerged as a powerful platform for the development of many desktop applications. We first present a review of popular QoS-aware standard networking APIs available to developers on both UNIX and Windows systems. We then discuss by design and implementation extensions we made to the Java architecture to support QoS over native asynchronous transfer mode (ATM) networks. Our implementation offers Java application developers the ability to specify their QoS requirements over ATM networks and simultaneously takes advantage of platform independence provided by Java. In addition, we discuss practical performance experiences obtained with our design in supporting digital video applications running over ATM networks.