A package of six fully interactive energy software programs was developed for educational use. The first three programs can be used to simulate energy systems, while the rest three can be used to calculate some characteristic values, which can be used separately or in conjunction with the first three programs. The first one is a multimedia program for an active solar hot water system. It accounts for a large number of parameters and can be used to investigate their effect on the thermal efficiency of the system. The second program is a transient simulation for thermal behavior of a building. It can be used to predict the temperature and relative humidity inside a building along with the heating/cooling load required to keep the temperature at a preset point. The third program has been developed for sizing solar thermal systems. The fourth program is a graphical representation of the apparent motion of the sun on the celestial vault. The fifth program calculates the thermophysical properties of a number of gases and liquids for a desired temperature. The sixth program represents graphically the psychrometric chart. The above-mentioned programs, are useful tools for education in energy, suitable for high school students and Universities. It can also be used for an extensive set of exercises in the tertiary education sector. (c) 2006 Elsevier Ltd. All rights reserved.