This document describes the motivation for, elements of, and use of the zorder-lib, a library API that implements organization of and access to data in memory using either a-order (also known as "row-major" order) or z-order memory layouts. The primary motivation for this work is to improve the performance of many types of data- intensive codes by increasing both spatial and temporal locality of memory accesses. The basic idea is that the cost associated with accessing a datum is less when it is nearby in either space or time.

The Energy Sciences Network (ESnet) is the primary provider of network connectivity for the U.S. Department of Energy Office of Science (SC), the single largest supporter of basic research in the physical sciences in the United States. In support of the Office of Science programs, ESnet regularly updates and refreshes its understanding of the networking requirements of the instruments, facilities, scientists, and science programs that it serves. This focus has helped ESnet to be a highly successful enabler of scientific discovery for over 25 years. In April 2015, ESnet and the Office of Advanced Scientific Computing Research (ASCR), of the DOE Office of Science, organized a review to characterize the networking requirements of the programs funded by the ASCR program office. Several key findings resulted from the review - they are discussed in this report, along with the case studies presented at the review.