This talk will look at the drivers leading the way to Exascale computing. It will examine technology trends, and use these to infer some of the characteristics of future large scale HPC systems. It will also look in to what this means for the software environment, reliability, use and affordability of IT systems at the high end. Recently, the IT industry has become more focused on problems involving the use and management of large data sets (Big Data) and we map this trend on to the consequences of Exascale computing. What will future architectures look like, how will they be used, and what does that mean for applications development today?