Google's newscrawler turned up a nice find for me today with an English-language piece from Radio France International about a festival called Le Cabaret Vert. The festival is named after a poem by Rimbaud, who came from the same Ardennes region that the festival is held in. This year the event celebrated its fourth anniversary over the last 3 days of August.
The piece is available both as an article and as an audio piece (caution-Windows Media Player file) complete with a full-length track from an Atlanta-area hip-hop band. It's particularly interesting to note that the festival's reputation isn't based on the quality of music but instead on being a green festival that happens to have good bands. As unlikely as that might sound to American audiences, they managed to draw 35,000 to this year's event, about the same number of people who attended Rothbury.
Unfortunately, there's no English language version of the festival website, so I wasn't able to read about the specifics of what makes this festival so eco-friendly. The article mentions lots of recycling bins and an area where fans wash their own dishes instead of using disposable foodware, but other than that I'm not sure how this event stacks up.
Here's some kind of a promotional video for the 2007 version of the festival. I'm not really sure what's going on, but the French-rock soundtrack is pretty entertaining. Enjoy!