We at Total Film are still stunned and saddened by the Heath Ledger tragedy - and it seems Hollywood feels exactly the same way...
I worked on the same film and I never met him - we were never on the same set. This is as much news to me as anybody and it affects me in the same way.
The studio is stunned and devastated by this tragic news. The entertainment community has lost an enormous talent. Heath was a brilliant actor and an exceptional person. Our hearts go out to his family and friends.
Warner Bros president Alan Horn and studio president Jeff Robinov
I adored him. I don't know how to compare his talent to others but he's touched me deeply as a talent and it's a great loss - losing him at any age would be a loss but it was pretty rough news. I was really shocked by it.
I had such great hope for him. He was just taking off and to lose his life at such a young age is a tragic loss. My thoughts and prayers are with him and his family.
What a terrible tragedy. My heart goes out to Heath's family.
I am shocked and very saddened by the news. I deeply respected Heath's work and always admired his continuing development as an artist. My thoughts are with his family and close friends.
That's terrible. Drugs today... when we stopped taking drugs, they started. It is just an epidemic. I am sorry to hear that. He was a great talent.
It's really, really sad. I hope his family is okay. I wish them the best.
He made a decision about four years ago to stop being led by producers and managers and to forge his own way. He started working with the most interesting directors. He was so successful at breaking out of the teen idol image.
Neil Armfield, director of Candy
I went through a similar thing with River Phoenix in the fact that he was so young. It's a real tragedy when someone so talented dies because you don't know on the early part of their career what more they could offer us.
Director Rob Reiner
For more tributes, go to the BBC.