Wow... I can't believe that epic did this, and it makes me so very very happy. In case you didn't know, the unreal development kit (UDK) is the unreal engine 3 used to make games such as gears of war, unreal tournament 3, mirrors edge, bioshock and many others, and it has been made available to the public for game development. You cannot make retail games, unless you pay epic games royalties.It is very simple, yet extremely powerful.