From the reviews:
"... These three bulky volumes [EMS 124, 125, 127], written by one of the most prominent researchers of the area, provide an introduction to this repidly developing theory. ... These books can be warmly recommended to every graduate student who wants to become acquainted with this exciting branch of matematics. Furthermore, they should be on the bookshelf of every researcher of the area."
László Kérchy, Acta Scientiarum Mathematicarum, Vol. 69, 2003
"... The author has obviously put a tremendous amount of work into the writing of this book and he is to be congratulated for making it available to the operaotr algebra community. ..."
R.S.Doran, Mathematical Reviews Clippings from Issue 2004g
"Theory of Operator Algebras II" von Masmichi Takesaki ist der zweite Band eines dreibändigen Werks und behandelt neuere Entwicklungen in der Theorie der Operatoralgebren der letzten 20 Jahre. ......
Die Auswahl der Themen ist in erheblichem Maß durch die Entwicklung der nichtkommutativen Geometrie geprägt. Daher stellt das Buch eine äußerst nützliche Sammlung von theoretischem Hintergrundwissen dar, das für das Verständnis von Originalarbeiten der nichtkommutativen Geometrie notwendig ist, und in dieser kompakten Form bisher nicht zu finden war.
Geschrieben in einem schnörkellosen, aber klaren, didaktischen Stil ist dieses gut strukturierte Buch jedem zu empfehlen, der sich ernsthaft mit den Grundlagen der Operatoralgebra und der nichtkommutativen Geometrie auseinandersetzen will. ..."
Christian Blohman, for complete review see http://www.wissenschaft-online.de/artikel/714368
"This is the second volume of an advanced textbook written by one of the most active researchers in the theory of operator algebras and is useful for graduate students and specialists. ... Each chapter begins with a clear introduction describing the content of that chapter, contains several interesting exercises and is concluded with a section of rich historical notes." (Mohammad Sal Moslehian, Zentralblatt MATH, Vol. 1059 (10), 2005)
"This book, written by one of the world's most respected operator algebraists, is devoted primarily to the study of type III von Neumann algebras ... . It contains seven chapters and an extensive appendix ... . each chapter has its own introduction describing the content and basic strategy, enabling the reader to get a quick overview of the results. ... The author has obviously put a tremendous amount of work into the writing of this book and he is to be congratulated ... ." (Robert S. Doran, Mathematical Reviews, 2004 g)