Complex sentence: It is the soundtrack of the movie "A Map of the World" released in 1999 starring Sigourney Weaver, which in turn was based on the book "A Map of the World" by Jane Hamilton.
Split into simpler sentences: It is the soundtrack of the movie "A Map of the World" released in 1999 starring Sigourney Weaver. The movie was based on the book "A Map of the World" by Jane Hamilton.