While initially similar to the primary DC Universe, a few differences seem to be evident when one looks closely at this world. All of the heroes one would expect operate here. Batman, Wonder Woman, The Flash, Green Lantern and so on, as does the Justice League and the other well-known groups and individuals both villain and hero. However, the original Superman is gone, as is his arch-nemesis LexLuthor. Superman was last seen flying into the sun in order to repair the damage done to it by the Tyrant Sun, Solaris. LexLuthor was put to death by electric chair due to his part in the tragedy. The vast majority of the world believes Superman to be dead. However, Lex Luthor had cracked the genetic code of the Man of Steel and given it to Dr. Quintum of P.R.O.J.E.C.T. who, along with the help of Lois Lane and others, was able to imprint it upon the DNA of one of Lois' ovum, giving birth to a new Superman who would be a child of both Krypton and Earth.
DC Comics: All Star Superman-1