This is the home page of lmfit, a self-contained C library for Levenberg-Marquardt least-squares minimization and curve fitting.
For earlier changes, see CHANGELOG
For a gentle introduction to the Levenberg-Marquardt algorithm, see e.g. K Madsen, H B Nielsen, O Tingleff (2004): Methods for non-linear least squares problems.
The source package comes with build scripts generated by GNU autotools, to be run with the usual commands ./configure, make, sudo make install. To test, run examples in directory demo.