Michael Lang said plans for a 40th anniversary Woodstock concert are "all speculative ideas" for now, but he hopes to bring them to reality this summer.

The Woodstock co-founder told Billboard.com that his vision is "a free event...a very green project," possibly in New York City.  "We want to have as small a carbon imprint as we can and use as many green techniques as we can," said Lang, who was in Austin as part of a South By Southwest panel discussion about Woodstock. The holdup? "It's got to be sponsor-driven," he explained.

"It's free, but it costs a lot of money. That's kind of what we're in the middle of right now. Depending on how successful we are in raising that sponsorship (money) will determine when and how we do this event – or if we do this event, frankly."

He added that reports of a concurrent Woodstock festival in Berlin, possibly at Tempelhof airport, were "premature" but "still is kind of a thought."

Lang said that musically a 2009 Woodstock would go "back to its roots...There would be a lot of legacy bands – the Who, Santana, Crosby, Stills & Nash, Joe Cocker maybe. And it would be people like Steve Earle and Ben Harper. There's certainly room for the (Red Hot) Chili Peppers and Dave Matthews...That would be the shape of the music."

The Chili Peppers, of course, closed the ill-fated 30th anniversary concert in 1999, which was marred by complaints about the facilities, food and water prices and ended with a fiery riot. But Lang said he was confident that the Woodstock brand was not permanently damaged.

"I think it always hearkens back to the '69 event, somehow," he said. "When people think [of Woodstock] they don't think '99 or '94. They think [of] the '69 event. I think [1999] has its ramifications, but I don't think it did any real damage in that sense."

With or without concerts, Woodstock’s 40th will be celebrated with an array of projects this year. Lang has written a book, “The Road to Woodstock,” in collaboration with Holly George-Warren that will be published in July. He’s also working on a VH1/History Channel documentary with Barbara Koppel.

On June 9, meanwhile, Warner Home Video will release a four-hour director’s cut of the “Woodstock: 3 Days of Peace and Music” film featuring 18 new performances – including some from five groups (Creedence Clearwater Revival, the Grateful Dead, Johnny Winter, Mountain and the Paul Butterfield Blues Band) that did not appear in the original film. Rhino Recods will roll out a six-CD box set of Woodstock performances.

Director Ang Lee has made “Taking Woodstock,” a feature film about the real estate agent who helped the 1969 festival move to Bethel, N.Y., after losing permission to hold it in nearby Walkill.

At the South By Southwest panel, Lang joined several Woodstock staffers and artists in telling war stories about the original festival. Santana drummer Michael Shrieve noted that Woodstock "changed the course of my life. To this day not a day goes by when someone doesn’t bring it up," either in person or online. He and bandmate Greg Rolie also discussed whether guitarist Carlo Santana had taken acid or mescaline before the group went on – earlier, they noted, than expected.

Sha Na Na drummer Jocko Marcellino, meanwhile, noted that his group – the last to be booked for the festival – was paid a mere $350 and another $1 for movie rights. He also slept in the field, telling the other artists "I didn’t know you had those (backstage amenities)."

Recording engineer Eddie Kramer revealed that the Woodstock film crew ran out of stock and had to fly additional film from Chicago to Albany and then helicopter it to the festival site in Bethel.

Lang, meanwhile, concluded that "the stars of Woodstock were the people, this audience that came together and made something special."