There are many unexpected and exciting no-linear phenomena in zeolite diffusion and reaction, including shape selectivity, activation energies of diffusion, window effects and length selectivity, occupancy effects, and negative activation energies of reaction. There are a number of plausible theories on the origin of these wild phenomena, and many more experimental investigations are needed to prove or disprove these theories. Nonlinear phenomena are the origin of many breakthrough technologies in the electronics industry, including semiconductors and lasers. Outside of shape-selective catalysis, the commercial exploitation of these nonlinear phenomena in zeolite is a major challenge.