Over the past two decades metal–organic frameworks (MOFs) have emerged as an intriguing class of solid-state materials. This has been fueled by the synthesis of thousands of discrete examples of these materials through the judicious choice of their components, inorganic nodes organic linkers. MOFs are held together by coordinate bonds which bestows MOFs with a highly attractive set of characteristics; including: (i) crystallinity, leading to precise structural determination; (ii) synthetic tunability—pore size, shape, and functionality; and (iii) porosity, MOFs possess some of the highest known surface areas and pore volumes reported to date, and can be ultramicroporous, microporous, and/or mesoporous. These characteristics give rise to new and unique physical and chemical properties that are driving researchers to investigate the suitability of MOFs in a handful of practical applications. Examples include gas storage, chemical separations, catalysis, sensing, conductivity, solar fuels conversion, light harvesting and energy conversion, and magnetic materials amongst others.