Roger Ebert, the Pulitzer Prize-winning critic who taught generations of writers and audiences how to talk about film, passed away today, his longtime employer the Chicago Sun-Times reports. He was 70.

A vocal advocate for good movies, even after cancer claimed his voice and lower jaw in 2006, Ebert never relented, penning more than 200 reviews a year for the newspaper that had been his home for close to five decades. Last year, the most productive of his career, he wrote "306 movie reviews, a blog post or two a week, and assorted other articles."

The longtime co-host of such movie-review television shows as Sneak Previews and Siskel and Ebert and The Movies (Gene Siskel died in 1999) also embraced the Internet and social media, writing frankly about movies, politics and his battle with cancer on his blog and on Twitter.

Always technically savvy — he was an early investor in Google — Ebert let the Internet be his voice," the Sun-Times notes. "His rogerebert.com had millions of fans, and he received a special achievement award as the 2010 'Person of the Year' from the Webby Awards, which noted that 'his online journal has raised the bar for the level of poignancy, thoughtfulness and critique one can achieve on the Web.' His Twitter feeds had 827,000 followers."

On Tuesday, the eve of his 46th anniversary at the Sun-Times, Ebert announced he was taking “a leave of presence" because of he had experience a recurrence of cancer following a hip fracture he suffered in December.

"At this point in my life, in addition to writing about movies, I may write about what it's like to cope with health challenges and the limitations they can force upon you," he said. "It really stinks that the cancer has returned and that I have spent too many days in the hospital. So on bad days I may write about the vulnerability that accompanies illness. On good days, I may wax ecstatic about a movie so good it transports me beyond illness."

Still, Ebert remained optimistic, discussing in the same essay his plans for a new online venture called Ebert Digital, which he would run with his wife Chaz Ebert and longtime friend Josh Golden, as well as the 15th annual Ebertfest at his alma mater the University of Illinois in Urbana-Champaign. And, of course, reviewing films.

He leaves behind his wife Chaz, a stepdaughter and two step-grandchildren ... and many, many admirers.