The ACE ORB (TAO) is a freely available, open-source, and standards-compliant real-time C++ implementation of CORBA based upon the Adaptive Communication Environment (ACE). It attempts to provide efficient, predictable, and scalable quality of service (QoS) end-to-end. TAO applies the best software practices and patterns to automate the delivery of high-performance and real-time QoS to distributed applications.