A difficulty in writing control software for research telescopes is designing sufficient flexibility to handle continually changing requirements. The primary goal of the control software architecture for NRAO's new 100-meter radio telescope in Green Bank, West Virginia is flexibility through the construction of a modular software system. Using the principles of modular design: the number of systems implemented to satisfy the required functionality between users and devices was minimized each device was implemented as an autonomous unit object-oriented design and C++ were used throughout the system The purpose of this report is to present the software architecture being used to achieve a modularity in the Green Bank Telescope.