This work presents a system for the hardware accelerated parallel rendering of large volume datasets on PC Clusters. The parallelization possibilities on the visualization pipeline are explained, and how some of this possibilities have been exploited. The evolution of commodity graphics hardware is also discussed, and serves as motivation for working on the parallelization of the last step of the visualization pipeline, namely the rendering of images. A comparison between ''high end'' proprietary visualization systems and commodity hardware is provided and serves as motivation for working on the parallelization of the rendering using clusters of PCs equipped with commodity graphics hardware. The parallelization of the volume rendering algorithm is presented, and special attention is paid to the parallelization of the compositing stage: two well known algorithms for parallel compositing, direct send and binary swap, are discussed and compared and a justification for choosing one over the other is provided. Assembler implementations of the compositing operation are given, one for the Intel's x86 architecture, and one for AMD's AMD64. The performance characteristics of this implementations are discussed. Remote access of generic visualization facilities is presented, including a detailed description of a generic method for remotely accessing visualization applications.