In this section, we review recent applications of reactive MLPs (RMLPs) to various reaction systems. We specifically focus on homogeneous molecular reactions and some material reactive systems. RMLPs can and have been applied to the prediction of energies/forces, barrier heights, reaction rates, optimized geometries/reaction pathways, and spectra. The game changing application is that of obtaining results that mimic those of high-level QM in terms of accuracy, but at a very reduced computational cost. In this paper, we classify these applications by the increasing complexity of reaction systems as follows: