%T oc\-X: an Optimising Multiprocessor occam System for the PowerPC %A Tim Sheen, Alastair R. Allen, Andreas Ripke, Stacy Woo %E Peter H. Welch, Andr\[`e] W. P. Bakkers %B Proceedings of WoTUG\-21: Architectures, Languages and Patterns for Parallel and Distributed Applications %X The development of a PowerPC port of the KRoC (portable occam compiler) is described. As well as the basic port, a multiprocessor run time system provides services for user programs, including efficient occam channels between distributed processes, natural access to host file systems and TCP/IP network sockets. Optimization of target assembly code is discussed, with methods for removing the inefficiencies introduced by the KRoC translation process.