Two-dimensional leaky-wave antennas (2-D LWAs) are a class of versatile planar radiators whose illumination function, and hence radiated field, is mainly established by the excitation of cylindrical leaky waves by a simple feeder. In recent years a number of 2-D LWA designs based on the use of multiple feeders have been proposed, exhibiting various kinds of advanced radiative performance at microwaves, millimeter waves, and even sub-millimeter waves. A review of such designs is presented in this work, along with recent developments aimed at various sensing and communication applications.