The article by Omar K. Farha and Joseph T. Hupp reviews recent advances in the design, synthesis, purification, and activation of metal–organic frameworks (MOFs). MOFs are hybrid materials with ultrahigh surface areas, low densities, and uniformly structured cavities, making them useful for applications such as gas storage, chemical separations, and catalysis. The authors highlight the challenges in obtaining pure MOFs and optimizing their structure, particularly in controlling catenation (the interpenetration or interweaving of identical networks). They describe methods to prevent catenation by designing organic struts that limit framework catenation, leading to larger pores. They also present a density-based separation method to purify MOFs from contaminants, and a supercritical carbon dioxide (SCCD) activation method to enhance porosity and surface area without pore collapse. These advances are expected to lead to new MOF structures and improved applications in various fields.The article by Omar K. Farha and Joseph T. Hupp reviews recent advances in the design, synthesis, purification, and activation of metal–organic frameworks (MOFs). MOFs are hybrid materials with ultrahigh surface areas, low densities, and uniformly structured cavities, making them useful for applications such as gas storage, chemical separations, and catalysis. The authors highlight the challenges in obtaining pure MOFs and optimizing their structure, particularly in controlling catenation (the interpenetration or interweaving of identical networks). They describe methods to prevent catenation by designing organic struts that limit framework catenation, leading to larger pores. They also present a density-based separation method to purify MOFs from contaminants, and a supercritical carbon dioxide (SCCD) activation method to enhance porosity and surface area without pore collapse. These advances are expected to lead to new MOF structures and improved applications in various fields.