Stephen King's IT isn't really similar to his book that he wrote in 1985 and published in '86, but that doesn't makes the movie less good. The makers of this movie rewrote the script very well into a successful movie, with actors as Tim Curry and Richard Thomas. The movie might be a big long, but the book wasn't too thin either; I've read the book and it contains 943 pages! The story knows two sides: one in the past, and one in our time. This is probably the cause of the long story. And of course the fact that you have actually seven heroes, each with their own lives. This is very good for the story of the movie, and makes the movie complete. Well done!