Freeware. 390 units in 46 categories. Has all basic categories and engineering specific categories like enthalpy, heat capacity, heat transfer coefficient, moment of inertia, surface tension, torque and viscosity. Converts feet and inches to and from decimal lengths. Converts between dynamic and kinematic viscosity. Steel hardness equivalents. Gas Constant in 900 sets of units. Excludes archaic units. Powerful formatting and clipboard features.

GOWProp
GOWProp calculates gas, oil and water PVT properties based on user selected method: - Gases: Natural Gas, Air and Nitrogen; - Liquids: Oil, Water, Methanol, MEG, DEG and TEG

DataFit
DataFit is a tool for performing curve fitting, statistical analysis & data plotting. Fit equations with up to 100 parameters to data with up to 20 independent variables. Define your own equations or choose from over 600 pre-defined equations.

ComfortAir HVAC Software
ComfortAir HVAC software is designed to be used by engineers, architects, contractors and energy auditors for calculating and analysing heating and air conditioning hourly loads in commercial buildings. Units can be set to English or Metric.

BeamBoy
BeamBoy is a free engineering utility for calculating stress and deflection of structural beams under load. May also be used for shafts. BeamBoy is menu-driven and intuitive.

Copan Pro
Copan Pro enables you to calculate coordinate geometry (COGO), process field surveys, adjust map traverses, perform map/deed closure checks, calculate areas and perimeters, transform coordinates, import/export Ascii files, and draw lines and symbols.