Low-cost, high efficiency, multipurpose and compact aircraft capable of Vertical Takeoff and Landing (VTOL) or Short Takeoff and Landing (STOL) flight have long been desired by the aerospace community. The channel wing concept, first proposed by Willard Custer in the late 1940s', is a promising candidate for efficient V/STOL performance. A channel wing has an upwardly opening semi-cylindrical channel placed near the aircraft fuselage. A propulsion unit is mounted in the channel; usually a propeller located towards the rear. When the propeller is operated at static or low speed conditions, the speed of the air flowing through the channel is much higher than that of the air flowing below the wing. As a result, high lift is generated. The concept was brought to life in prototype airplanes manufactured by the Custer Channel Wing Corporation in the 1950s' and the 1960s', but these designs had a number of problems. The improvements in aerospace technology since then and recent developments in circulation control technology may facilitate the realization of a superior channel wing configuration. This paper presents a comprehensive review of the most significant patents on this subject and concludes with comments on possible future developments.