To achieve accessible computational power for their research goals, the authors developed the tools to build easy-to-use, numerically intensive parallel computing clusters using the Macintosh platform. Their approach enables the user, without expertise in the operating system, to develop and run parallel code efficiently, maximizing the advancement of scientific research. Accessible computing power has become the main motivation for cluster computing - some wish to tap the proliferation of desktop computers, while others seek clustering because they find access to large supercomputing centers to be difficult or unattainable. Both want to combine smaller machines to provide sufficient access to computational power. In this article, we describe our approach to cluster computing to best achieve these goals for scientific users and, ultimately, for the mainstream end user.