Field-programmable gate arrays (FPGAs) are chips that can be electronically programmed to function as an arbitrary digital circuit or system. They were originally used to replace discrete gates in interface electronics, and over the past three decades have evolved to being used in the place of application-specific integrated circuits (ASICs) in low volume and cost-constrained situations. Modern commercially available FPGAs are sophisticated integrated circuits capable of implementing digital chips with millions of gates. In addition, some of them also have special-purpose I/O macros to support memory interfaces, as well as serial links to support high-throughput communication. FPGAs are widely used to prototype digital logic. This chapter discusses some of the challenges with using standard FPGAs to prototype asynchronous logic and summarizes research efforts that have created alternate FPGA architectures for asynchronous logic.