Computer architects should be looking towards alternative memory technologies as a compelling strategy to address the memory wall, especially in the context of increasing on-chip memory capacity and efficiency.  However, there are many distinct technology proposals and memory properties, which makes it challenging to compare and match potential solutions to system and application contexts. NVMExplorer is one set of tools to enable this kind of research because it allows for comparison, as well as probing cross-computing-stack design choices, and we hope it is a starting point for many future design space exploration and system design and optimization efforts.