The third session of IT@EDU98 consisted of five papers on educational software and was chaired by Tran Van Hao (University of Education, Ho Chi Minh City, Vietnam). "Courseware Engineering" (Nguyen Thanh Son, Ngo Ngoc Bao Tran, Quan Thanh Tho, Nguyen Hong Lam) briefly describes the use of courseware. "Machine Discovery Theorems in Geometry: A Helpful Tool in Teaching Geometry" (Hoang Kiem, Vu Thien Can) describes a system for discovering and proving theorems in the domain of plane geometry. "Model of Problems in Analytic Geometry and Automatically Solving" (Do Van Nhon) proposes a general model that can be used for representing problems of 3-dimensional analytic geometry. "Heuristic Based Scheduling in High School" (Nguyen Duc Thang) addresses scheduling teachers and classes in a high school. "A Model of Knowledge of Analytic Geometry" (Do Van Nhon) proposes the AG model, a model that can be used for representing knowledge of 3-dimensional analytic geometry, and discusses problems with constructing the knowledge base of 3-dimensional analytic geometry. (SWC)