Cloud computing for high performance computing users has been the subject of great interest since the mid-2000s, but it is only relatively recently that the range of CPU and memory options, networking, ecosystem of software licenses, and cultural factors have been in place to make it thrive. In this 2017 edition of The State of HPC Cloud, veteran journalists and analysts in the HPC and cloud space, Nicole Hemsoth and Timothy Prickett Morgan, look at the variety of technology developments that have made cloud-based supercomputing possible as well as how other factors, including the expansion of use cases for HPC cloud, are pushing this area forward. In addition to focusing on traditional supercomputer applications, the authors also look at the ties between HPC and machine learning clouds as similar hardware and performance constraints drive each in cloud-based environments.