J. R. R. Tolkien's fantastical works have served as the inspiration to painters, musicians, filmmakers and writers, to an extent that Tolkien is sometimes seen as the "father" of the entire genre of "high fantasy". The production of such derivative works is sometimes of doubtful legality, because Tolkien's published works will remain copyrighted until 2043. The film, stage and merchandise rights of The Hobbit and The Lord of the Rings are owned by Tolkien Enterprises, a division of the Saul Zaentz Company, while the rights of The Silmarillion and other material remain with The J.R.R. Tolkien Estate Ltd., a company owned by Tolkien's heirs.