Filzbach is a flexible, fast, robust, parameter-estimation engine that enables you to parameterize arbitrary, non-linear, parameter-rich models—of the kind that are necessary in biological sciences, for example--against multiple, heterogeneous data sets. Filzbach supports Bayesian parameter estimation, maximum-likelihood analysis, priors, latents, hierarchies, error propagation, and model selection. The Filzbach package can be used with Visual Studio 2010 or Visual Studio 2010 Express.