Polish author Stanislaw Lem, most famous for science fiction works including Solaris, has died aged 84, after suffering from heart disease.
Lem's works sold more than 27 million copies
He sold more than 27 million copies of his works, translated into about 40 languages, and a number were filmed.
His 1961 novel Solaris was made into a movie by Russian director Andrei Tarkovsky in 1971 and again by American Steven Soderbergh in 2002.
Soderbergh's version starred George Clooney and Natascha McElhone.
Lem was born in 1921 in Lviv, then a Polish city but now part of Ukraine. He studied medicine there before World War II. In 1946 he moved to Krakow.
He concentrated on science fiction writing, a genre regarded by the Polish socialist government as fairly harmless in terms of censorship.
However, his first major novel, Hospital of the Transfiguration, went unpublished for eight years until the ideological thaw that followed Soviet leader Josef Stalin's death in 1953.
Other key works included The Cyberiad in 1965.
After the collapse of communism in eastern Europe, Lem turned to writing reports on future trends, including computer crime and the ethical problems of the internet.