Mview for MATLAB is designed to manipulate and display up to 20 data files. Like Mfit, it is also a point-and-click application. A link with MFit permits to fit each data set. Basic operations are possible.
MATLAB 5.2 (R10)
It requires load routines, fit functions and routines from MFit (see that package).
See also http://www.ill.fr/tas/matlab/doc/