Everyone working on quantum information theory has his or her favourite interpretation of quantum mechanics. Those interested in the history and philosophy of quantum mechanics will find an interesting presentation of philosophical controversies concerning quantum mechanics in the recent book "Quantum" by Manjit Kumar. Graham Farmelo, the author of “The Strangest Man,” a biography of Paul Dirac, in his review written for New York Times writes: ''[..] Manjit Kumar cites a poll about the interpretation of quantum mechanics, taken among physicists at a conference in 1999. Of the 90 respondents, only four said they accepted the standard interpretation taught in every undergraduate physics course in the world. Thirty favored a modern interpretation, laid out in 1957 by the Princeton theoretician Hugh Everett III, while 50 ticked the box labeled "none of the above or undecided." Almost a century after a few physicists first set out the basic theory, quantum mechanics is still a work in progress.''