PEST

A model-independent, nonlinear parameter estimator. The nonlinear parameter estimation algorithm used by PEST is uniquely robust and powerful having been developed for use with complex environmental models. The purpose of PEST is to assist in data interpretation, model calibration, and predictive analysis.

PEST is fully integrated into the GMS interface, allowing you to perform advanced parameter estimation for MODFLOW models.

To learn more about PEST visit the following site:
www.parameter-estimation.com/...pest

For more detailed information on PEST visit the GMS wiki at:
www.xmswiki.com/...PEST