Deploying and controlling experiments running on a distributed set of resources is a challenging task. Software developers often spend a significant amount of time dealing with the complexities associated with resource configuration and management in these environments. Experiment control systems are designed to automate the process, and to ultimately help developers cope with the common problems that arise during the design, implementation, and evaluation of distributed systems. However, many of the existing control systems were designed with specific computing environments in mind, and thus do not provide support for heterogeneous resources in different testbeds. In this paper, we explore the functionality of Gush, an experiment control system, and discuss how it supports execution on three of the four GENI control frameworks.