This thesis presents the design and evaluation of an operating system kernel specially designed for dataflow software. Dataflow is a style of software architecture that is well suited for control and "signal flow" applications. This architecture involves many small processes and lots of inter-process communication, which impose too much overhead on traditional RTOSes. This thesis describes design and implementation of the Dataflow Architecture Real-time Kernel (DARK). DARK is a reconfigurable, multithreaded and preemptive operating system kernel that introduces a special data-driven scheduling strategy for dataflow applications. It uses the underlying hardware for high-speed context switching between the kernel and applications, which is five times faster than the ordinary context switch. The features of the kernel can be configured according to performance requirements without change to the applications. Along with the performance evaluation of DARK, the performance comparison results of DARK with two commercial RTOSes: MicroC/OS-II and Analog Devices VDK++ are also provided.