GasTurb is used by engineers and managers in the gas turbine industry and in universities and academies in 23 countries, including the USA and Canada. GasTurb is

User friendly - just input a few data, point and click. Easy to use even for those with limited computer experience.
Accurate - gives the same results as the complicated cycle performance programs used by major aircraft engine companies.
Written by a professional with more than 25 years experience in gas turbine performance.
Compatible with Windows 95, 98 and Windows NT, Windows 2000, Windows XP
Requires only 5 MB free RAM and 17 MB disk space.