NEW YORK -- For a week in May, YouTube will turn into the biggest open mic on the planet.

On Thursday, the Google Inc.-owned site will announce the YouTube Comedy Week, a seven-day cyber extravaganza designed to showcase some of the best comedy across its expansive video platform. From May 19-25, YouTube will be overrun with punch lines, sketches, stand-up routines and -- hopefully -- a lot of laughs.

It's the largest-scale attempt yet by YouTube to program its billions of hours of video and lead viewers to its growing channels of original programming. The video site is planning more event weeks around various themes to be held later this year and beyond.

"This has never been done before on YouTube," Danielle Tiedt, YouTube's vice-president of marketing, said in an interview Wednesday ahead of the announcement. "I'm sure we'll learn a lot."

Comedy Week will kick off with a global live stream from Los Angeles' Culver Studios. Throughout the week, new episodes will debut from some of YouTube's most popular channels, comedians will perform and comics will curate lists of their favourite videos.

Among those participating are Ricky Gervais, Sarah Silverman, Rainn Wilson, Michael Cera, Vince Vaughn and Seth Rogen. There will be new videos from Andy Samberg's Lonely Island troupe. Popular comedy destinations with channels on YouTube like The Onion, Nerdist, College Humor and Funny or Die will join in. And YouTube hopes its less famous users will also get in on the act.

The event is just the start of a new approach by YouTube to congregate its disparate stars -- from Hollywood professionals to Internet upstarts -- and to present a unified viewing experience for users. YouTube hopes the theme weeks will spotlight the original programming the site has invested hundreds of millions of dollars in to grow its platform as a kind of next-generation TV.

"We're hoping to do this in a pretty regular rhythm," said Tiedt. "You'll see several of these coming from us, for sure, as we highlight really big areas that we think are amazing areas of strength for YouTube."

The undertaking is months in the works. To executive-produce the weeklong event, YouTube brought in former "Jimmy Kimmel Live!" producer Daniel Kellison, whose production company, HaChaCha, recently launched two comedy YouTube channels: Jash and the Video Podcast Network. The kickoff live stream will be directed and produced by Joel Gallen, a veteran of the MTV Movie Awards.

Kellison says a staff of 40 has been assembled to help in what he calls the "tremendously daunting" task of organizing a sizable portion of the sprawling YouTube realm.

"It's a massive undertaking," he says. "If you try to organize it all and figure it all out, you'll drown. It's not possible. We're just doing the best we can in trying to produce this."

A few missteps are inevitable, Kellison says. But the plan isn't to put on a slickly produced show, but something more lo-fi and relaxed.

"We've been able to go to all these comedians and say, 'Hey, we can do whatever we want and have fun doing it,"' says Kellison. "It's taken on this sort of comedy Woodstock type of vibe."

The duo of Eric Wareheim and Tim Heidecker, known as Tim & Eric, will be performing in the festivities. Wareheim, among the founders of Jash, believes Comedy Week will help raise the bar for comedy on YouTube.

"It's going to be higher production value, everyone taking it a little bit more serious rather than a throwaway Internet short -- make it a place where legitimate stuff can be and change the perception of what YouTube can be," Wareheim says. "Tim and I have been using YouTube for our TV shows, our movies -- for everything -- to kind of promote stuff. Now instead of just as a promotional tool, we're using it to really distribute content."

Getting even a segment of YouTube to synchronize would seem a tall order. But marshalling together Comedy Week reminds Kellison of the chaotic first night of "Jimmy Kimmel Live!"

"We had Coldplay on the outdoor stage; Warren Sapp coming in after he won the Super Bowl on a helicopter; Jon Gruden cancelling; the fire marshal trying to shut us down; Snoop Dogg with the death threats; and a buzzed George Clooney," he recalls. "I imagine this will be very similar."