In 2010, it was announced that "Lemmings" would be ported to the iOS operating system by developer Mobile 1UP. On 29 June 2010, Mobile 1UP reported that Sony Computer Entertainment Europe had presented them with a cease-and-desist letter, forcing them to halt development of the port. In April 2011, Mobile 1UP has released a re-worked version of the work done in 2010 with a prehistoric setting (new artwork, sfx, music, levels) under the name "Caveman", available for the iOS and webOS platforms. Brutal Deluxe, the developer who did the porting of the Apple IIGS version of Lemmings, has released the games' source code.