The Platform-Aware Compilation Environment (PACE) is an ambitious attempt to construct a portable compiler that produces code capable of achieving high levels of performance on new architectures. The key strategies in PACE are the design and development of an optimizer and runtime system that are parameterized by system characteristics, the automatic measurement of those characteristics, the extensive use of measured performance data to help drive optimization, and the use of machine learning to improve the long-term effectiveness of the compiler and runtime system.