Nemesis is an operating system designed by the University of Cambridge, the University of Glasgow, the Swedish Institute of Computer Science and Citrix Systems. Nemesis was conceived with multimedia uses in mind. In a microkernel environment, an application is typically implemented by a number of processes, most of which are servers performing work on behalf of more than one client. This leads to enormous difficulty in accounting for resource usage. In a kernel-based system, multimedia applications spend most of their time in the kernel, leading to similar problems.