Yesterday, apparently. A fine science fiction writer whose works were, according to IMDB, barely represented in the movie stakes. His only novel to make it to the big screen was Make Room! Make Room!, which became Soylent Green with Charlton Heston.
Which is a pity, because many of his books would have made lighthearted adventure movies, such as the Deathworld and Stainless Steel Rat series. Later he did some excellent epic-style SF West of Eden and its sequels, alternate histories in which dinosaurs did not become extinct.
He disagreed with Heinlein’s Starship Troopers, and did so in the best way by writing a satire on the novel, Bill, the Galactic Hero.
I’m startled to see that his first novel didn’t appear until 1960. I had always thought him more a contemporary of the Heinleins and the Azimovs. But he was certainly a fitting successor.