Beijing East Simulation & Software Technology ltd. (ESST) is a high-tech company which was founded in Beijing in 1992. ESST specializes in simulation software development and service, its major business areas include contracting projects and developing process simulation software in Petro-chemical, petroleum,chemical industry（Coal-chemical Industry),non-ferrous metal industry,water treatment, providing computer-based teaching (CBT) simulation and multimedia software for high education and professional education fields.