Abstract: A Robotic Autonomous Observatory (RAO) is a telescope that can perform various remote observations and adapt to changes during a task execution without human assistance. Currently, there are more and more RAO projects dedicated to follow-up observations of γ-ray bursts(GRBs) and supernovae. The RAO technology also shows more advantages as the time-domain astronomy develops. The software system plays a key role in an RAO system, since it is used to control the hardware devices and to schedule the entire observing process. The RTS2 (Remote Telescope System-2^nd version) is an open-source project aimed at developing a software environment to control a fully robotic observatory. It has been developed for more than 10 years. As the RTS2 project advances, many additional functions have been added, making the architecture of RTS2 more stable and mature. The RTS2 is based on the "plug and play" design. Each part of the system can be started, restarted, or stopped at anytime. Another highlight for the RTS2 is that there are dummy devices in an RTS2 system, providing a virtual environment for development tests. Due to the open-source and good-scalability characteristics, an RTS2 system is rather suitable for secondary developments to fit a new telescope. Nowadays, many RAO projects have installed RTS2 systems for the control of the telescopes. This paper first reviews the history and current situation of RAO, and then introduces our RTS2 software in detail. After that, the paper discusses the feasibility of a secondary development of an RTS2 system. The paper finally shows a design of a driving program for an RTS2 system to control a small equatorial (Synta NEQ6). This success lays the foundation for independent developing an RAO system based on the RST2.