is a framework for instantiating an ad-hoc computing infrastructure on top of distributed computing resources. Such resources include commercial computing clouds (e.g. Amazon EC2), scientific computing clouds (e.g. CERN lxcloud), as well as the machines of users participating in volunteer computing projects (e.g. BOINC). Co-Pilot provides components for building a framework for seamless and transparent integration of these resources into existing Grid and batch computing infrastructures exploited by the High Energy Physics community.