Rommel's Africa Corps used the 88mm anti-aircraft gun as anti-tank gun, and was proved effective.
88mm gun was in action till the end of war
8.8 cm Flak 37 - an updated version of the Flak 36, the main difference being Übertragungser 37 (a data transmission system)
8.8 cm Flak 41 - Luftwaffe asked for a new 88 mm design weapon defending against high-flying aircraft in 1939. Rheinmetall developed Flak 41 with longer cartridge & barrel. It featured a lower silhouette on its turntable mounting than did 8.8-cm Flak 18/36/37 on its pedestal mounting. (firing rate: 20~25 rounds / minute, effective ceiling of 11,300 to 14,700 meters). 556 were built from March 1943 to January 1945.