If there is a living legend among Sci-fi writers it is Frederick Pohl. At age 89 Pohl is still active, recently completing a novel in 2008 (The Last Theorem), co-written with the late Arthur C. Clarke. Pohl was editor of the Sci-Fi Pulps Astonishing Stories and Super Science Stories from 1939 – 1943. He served as editor of Galaxy magazine from the 1950s until 1969. Pohl won consecutive best Novel Nebulas in 1976 (Man Plus) and 1977 (Gateway). Gateway also captured the 1978 Hugo. His collaboration with Jack Williamson on the Undersea Trilogy is a classic. Member of the Sci-Fi Fall of Fame and a SFWA Grand Master.
Frederik Pohl has been about everything that it is possible to be in the field of science fiction, from consecrated fan and struggling poet to critic, literary agent, teacher, book and magazine editor and, above all, writer.
Called by Kingsley Amis (in Amis's critical study of science fiction, New Maps of Hell) "the most consistently able writer science fiction, in its modern form, has yet produced," Frederik Pohl is clearly in the very first rank of writers in the field.