On Feb. 25, 2009, science-fiction author Philip Jose Farmer died at home in Peoria, Ill., where he lived for much of his life. Born in Terre Haute, Ind., in 1918, he was 91 years old, and left behind a legacy of more than 60 novels and more than 100 shorter works, many of which are considered highly influential to the field. He is survived by his wife Bette as well as numerous children, grand children and great-grandchildren.

Farmer first gained recognition with the 1952 publication of his story "The Lovers," which for the first time introduced strong sexual themes into science fiction, and earned Farmer his first Hugo Award as "Most Promising New Writer." He continued to explore sexual themes in much of his short science fiction throughout the 1950s, and these seminal works were collected in book form as Strange Relations in 1960. In the late 1960s, he added two sexually themed novels, Image of the Beast and Blown. He was nominated for five Hugo Awards for short fiction in the 1960s, winning for "Riders of the Purple Wage."

In the 1960s, he introduced his popular World of Tiers novels, starting with The Maker of Universes (1965) and continuing with four more novels over the next 12 years, and completed with two more in the early 1990s. Set in alternative universes, these novels were highly influential in the field among authors of science-fiction and science-fantasy adventure.

In the 1970s, he introduced the Riverworld series, starting with To Your Scattered Bodies Go (1971), which became arguably his best known work, and won the Hugo Award in 1972. It was followed by four more novels, culminating in Gods of Riverworld (1983). (Farmer actually wrote the first Riverworld novel in the early 1950s, but the manuscript was lost for several decades before an early version was found and published in 1983 as River of Eternity.) The Riverworld novels were set on an artificially constructed world where all humans who had died throughout history were resurrected.

Farmer also garnered some controversy in 1975 with his pseudonymous publication of the very popular novel Venus on the Half-Shell by "Kilgore Trout," the fictional science-fiction author created by Kurt Vonnegut. Many fans of Vonnegut assumed that he was the author, which resulted in some friction between Vonnegut and Farmer. Farmer also wrote a number of very popular novels based on early pulp adventure fiction heroes such as Tarzan and Doc Savage, which were tied together in his Wold Newton universe. Also notable was his Dayworld series of three novels written in the late 1980s, set in a world so overcrowded that people had to live in shifts.

Farmer continued to be active until the long stay in intensive care that preceded his death, both in science-fiction and local activities in Peoria with the local library.