Mantevo is a multi-faceted application performance project. It provides application performance proxies known as miniapps. Miniapps combine some or all of the dominant numerical kernels contained in an actual stand-alone application. Miniapps include libraries wrapped in a test driver providing representative inputs. They may also be hard-coded to solve a particular test case so as to simplify the need for parsing input files and mesh descriptions. Mini apps range in scale from partial, performance-coupled components of the application to a simplified representation of a complete execution path through the application.