Information from the Chessbase website:
The Gruenfeld is one of the most aggressive openings against 1.d4, and it’s no wonder that Garry Kasparov has included it into his opening repertoire. Playing with White, one is well-advised to accept the challenge since in the harmless variations it’s usually already Black who dictates the course of action. In the main lines, however, theoretical knowledge is of great importance. Knut Neven has taken on the great task of arraning the huge amount of data – all more than 60,000 games – in a clear-cut way, appropriately dealing with all important variantions.