The Porous material Analysis Toolbox (PATO) is a modular analysis platform for multiphase porous reactive materials. It can be run as a simple Fourier heat transfer code or include more advanced features as internal decomposition (pyrolysis, vaporization), gas-gas and gas-solid chemical interactions (combustion, cracking, coking), gas species transport (convection, diffusion), and solid morphology evolutions (internal density changes, surface ablation). PATO is implemented as a C++ top level module of the open source (GNU GPL) computational fluid dynamics software program OpenFOAM. PATO also uses the open source (GNU LGPL) thermodynamics, transport, and chemistry library Mutation++ produced by the von Karman Institute for Fluid Dynamics.