Imprecise Probability Propagation Toolbox (IPP Toolbox). The IPP Toolbox is a collection of methods for uncertainty quantification and propagation using Dempster-Shafer Theory and imprecise probabilities. It runs under MATLAB 6.5 and higher. The IPP Toolbox provides all necessary functions to conduct an uncertainty analysis in the imprecise probabilistic framework. For those, who are looking for an alternative method to probabilistic uncertainty modelling, the toolbox offers a set of helpful functions. Methods for the quantification of uncertainty by imprecise distributions and the propagation through complex system models are supported. This toolbox is a library of functions that are highly configurable to the user’s needs. Uncertainty measures are included, as are sensitivity analysis methods. In the documentation section, some tutorials illustrate how to use the different functions.