From:
http://www.penguinputnam.com/static/packages/us/about/adult/ace.htmAce Books was founded in 1953 by A. A. Wyn, and is the oldest continuously operating science fiction publisher in the United States. With Donald A. Wollheim as editor, it issued some of the most outstanding science fiction writers of the 1950s and 1960s, including Samuel R. Delany, Philip K. Dick, Ursula K. Le Guin, and Robert Silverberg. Ace was known for marketing innovations such as the Ace Doubles, which contained two short novels bound back to back, and for the critically acclaimed Ace Specials edited by Terry Carr. In 1972, Wollheim left the company, and it was later acquired by Grosset & Dunlap. Under Publisher Tom Doherty, Ace produced books in all genres, though science fiction remained a specialty.
In 1982, Grosset & Dunlap was acquired by G. P. Putnam's Sons (later known as The Putnam Berkley Group), and Ace soon became Berkley's science fiction imprint. The combined backlists of Ace and Berkley made a powerful presence in the science fiction field, with Frank Herbert's bestselling Dune series, T. H. White's classic Arthurian novel The Once and Future King (basis for the musical Camelot), and much of Robert A. Heinlein's adult fiction, including Stranger in a Strange Land. More recent important authors include Joe Haldeman, winner of the 1998 Hugo and Nebula awards for Forever Peace, and William Gibson, whose Neuromancer is credited with having introduced the concept of cyberspace.