Last week's O'Reilly Tools of Change conference at the Sheraton in New York City marked the pioneering digital publishing conference's fifth anniversary, with the show on an upward growth trajectory not unlike that of the e-book. Since its inaugural event, which drew 400 to San Jose, Calif., in 2007, attendance at ToC has more than tripled, with nearly 1,400 total attendees at this year's show, another sellout, and its biggest conference to date.

"For me the biggest change is that the first one was kind of a tough sell at first," said Andrew Savikas, reflecting on the conference's history. "In 2007, a lot of people were just getting comfortable with what the Web had to offer, and the Silicon Valley perspective was new for a lot of this audience. Now, and it happened very quickly, almost everything has something to do with technology and digital publishing."

At the first ToC conference, there was no Kindle, Kobo, or Nook, no iPhone, no Google eBooks, no EPub, and Google was being sued over its library program, Savikas noted. Jimmy Wales spoke about Wikipedia, Chris Anderson about "free," and Tim O'Reilly about the power of Web 2.0 and user-generated content. In his keynote address, HarperCollins CEO Brian Murray, spoke of building proprietary platforms and building traffic for the publisher's Web site. "The big question," he said, "is cost." There was some discussion about e-books, Savikas recalled, but there wasn't a platform or market for consumers—and Manolis Kelaidis, a designer at the Royal College of Art in London, showed off a prototype of an enhanced digital book that had attendees buzzing about the possibilities.

As this year's conference opened, e-books are surging. Amazon has reported that it now sells more Kindle editions than paperbacks. And since last year's conference, the iPad has launched and become the fastest-selling consumer electronic device in history, bringing with it a vibrant new app market. So, too, has Google eBooks, making three million e-books available, many for free, spreading its cloud-based vision to the publishing world.

Savikas, meanwhile, noted the rise of another new, powerful technology: "ToC 2009 was the first time I remember noticing that Twitter had become this really important communication backchannel, where people were deciding where to go in real time," he said. "For a while during the 2009 event," he recalled, "we were even in the top trending topics."

For more on this year's ToC, check out our coverage online at www.publishersweekly.com/toc2011.