MINUIT is a collection of fortran77 code that can perform non-linear optimization with continuous parameters. That is, it searches for the minimum of a real function of a given set of real parameters, using a variety of algorithms. It gives parameter values of the minimum, parameter errors, as well as the covariance matrix (parameter cross-correlations). All these features make it the best available minimizer for maximum-likelihood fits, as used in data analysis of many scientific experiments.

MINUIT was written by a group of scientists at CERN and is now part of the CERN program library (CERNlib). CERNlib is available under the GNU Public License.

The only problem with using MINUIT in a modern environment is its language (fortran77), which is not necessarily every programmer's favourite. C-MINUIT was created to make it reasonably easy to use C (or Objective C, or C++) for writing the function to be minimized while using the fortran77 code of MINUIT to minimize it. The interface is provided by cfortran.h by Burkhard Burow, which is also available under a liberal licence. The C-MINUIT package is a ready-to-use collection of MINUIT and cfortran.h as well as an automatic configuration mechanism (using GNU autoconf/automake) and a simple example program.