One of the earliest books I ever remember reading (other than the Oz books) was "A Wrinkle in Time". I didn't realize the author was still alive, and now she isn't: Madeleine L'Engle has passed away, and we've lost still another great author. At least she left behind a great body of work, which hopefully will continue to be read for generations to come.
Has there ever been a movie based on one of her books? If not, why not?