Complex sentence: Given that MPI has now emerged as the de facto standard for message passing on computer clusters, the increase in the increase in the number of cluster nodes has resulted in continued research to improve the efficiency and scalability of MPI libraries.
Split into simpler sentences: Given that MPI has now emerged as the de facto standard for message passing on computer clusters. As cluster sizes have grown, this has resulted in increased research to improve the efficiency and scalability of MPI libraries.