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.
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Auto2Fit 

nonlinear regression global optimization genetic algorithms curve fit

EasyFit 

EasyFit is a distribution fitting software for Windows. It supports both classical (Exponential, Gamma, Lognormal, Normal, Weibull) and advanced distributions, basic statistics, goodness of fit tests, and high-quality graphs (PDF, CDF, survival etc.)
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