OpenPAT (the Open Performance Analysis Toolkit) is a dynamic trace analysis system that can be used to identify performance bottlenecks, monitor memory usage, for Search-Based Software Engineering and to visualize and model the performance of new High-Performance Computing architectures and distributed communication methods.OpenPAT integrates with platform specific compiler chain tools which allows it to remain simple with a core toolkit code base of less than 1000 lines and also to provide cross platform analysis for programs written in any compilable language including native languages like C, C++ and Fortran and languages that compile to bytecodes like Java and C#.