"Roger, I hope you're in an infinite movie palace, watching every film the great directors only dreamed of making," wrote comedian Patton Oswalt on Twitter moments after news of the 70-year-old's death broke. "By the way, Death's about to get a SUPER [crappy] review."
On his website Tuesday evening, Ebert said he was receiving radiation therapy to treat a hip fracture that had turned out to be cancerous. He said he planned to take a "leave of presence," continuing to write reviews but only selectively.
Via Twitter, actor Lou Diamond Phillips described the critic as a "wonderful man" who was "always more than kind to me."
"He wrote intelligent, informed criticism without being petty or cynical," said the "La Bamba" star.
Actress Holly Robinson Peete said she was sending prayers to Chaz Hammelsmith, Ebert's "beautiful and stoic wife" to whom he had been married since 1992.
As screenwriter Seth Grahame-Smith lamented on Twitter: "The balcony is closed," referring to Ebert's famous sign-off with the late Gene Siskel on his television review program "At the Movies."
Additional reactions to Ebert's death follow below.