Next generation real-time systems will require greater flexibility and predictability than is commonly found in today's systems. These future systems include the space station, integrated vision/robotics/AI systems, collections of humans/robots coordinating to achieve common objectives (usually in hazardous environments such as undersea exploration or chemical plants), and various command and control applications. The Spring kernel is a research oriented kernel designed to form the basis of a flexible, hard real-time operating system for such applications. Our approach challenges several basic assumptions upon which most current real-time operating systems are built and subsequently advocates a new paradigm based on the notion of predictability and a method for on-line dynamic guarantees of deadlines. The Spring kernel is being implemented on a network of (68020 based) multiprocessors called SpringNet.