DMFitter ActiveX control allows you to add sophisticated regression analysis tools to your software in a few lines of code. Features include: both linear and nonlinear (Levenberg-Marquardt) least squares curve fitting algorithms, arbitrary user models (defined analytically or by string expressions), double precision input vectors of any size, event support, weighting, wide set of functions and operators and unlimited number of fitting parameters. Examples for Excel, VB, Delphi, MSIE, Data Master 2003 and scripting languages are included.