While metal-organic and covalent organic frameworks are still in their infancy compared to zeolites, their versatility and nearly unlimited tunability endow these materials with an enormous potential as heterogeneous catalysts. In a recent review, to be published in Chemical Society Reviews, we highlight how recent advances, both in synthetic conditions as well as in modelling and characterization tools, contribute to unprecedented insight in heterogeneous catalysis and may be a game changer in catalyst design for a number of processes currently dominated by homogeneous catalysts. This review, which is part of a Chemical Society Reviews special issue on MOFs and is featured on the front cover, was coordinated by prof. Jorge Gascon from TU Delft and prof. Veronique Van Speybroeck from the Center for Molecular Modeling, in collaboration with the experimental groups of Francesc X. Llabrés i Xamena, Enrique V. Ramos-Fernandez, and Marco Daturi. This review forms a milestone within the ERC DYNPOR grant and DEFNET programme, which focus on the investigation of complex chemical transformations in nanoporous materials.