Nu-metal band Slipknot last played the Download Festival in 2005
Seventy-nine thousand people have arrived on site for this year's Download rock festival.
The three-day event, held at Leicestershire's Donington park race track, is now in its sixth year.
Headlining the main stage in 2009 are reformed 90s American rock band Faith No More, metal collective Slipknot and Sheffield's Def Leppard.
Limp Bizkit, Trivium, The Prodigy, Pendulum, Whitesnake and Anvil will also perform throughout the weekend.
Opening the main stage on Friday afternoon (12 June) were Californian rap-metal crew Hollywood Undead.
Welsh band The Blackout have also appeared and covered headliner Faith No More's Epic.
Matt Stourbridge from Brighton arrived on site early on Friday morning. He said: "The line up is amazing. I'm interested to see if Limp Bizkit are still any good.
"The Prodigy's going to be mad in the tent tomorrow."
The main stage will on Friday evening see performances from Korn, Limp Bizkit and Faith No More, playing their second UK gig following an 11-year hiatus.