HOLLiAS MACS-SCADA is a multi-functional, flexible, and distributed integrated-monitoring, data acquisition, and data integration software package which uses an open-framework software system, and multiple-platform support mode. Every layer is uniquely designed, logic-related, and expandable, enabling the system’s openness to be readily expanded. In this design mode, the application design and engineering experience is reused, where the software has a modular structure, supports platform sharing, and component reusing. This software incorporates the HollySys’ professional experience in the SCADA field and needs of clients, especially high-end leading industry clients like the China Railway Corporation. Continuous improvements have been made during the last decade to make this into a leading standard in the Chinese SCADA industry.