IBM and the Holocaust: The Strategic Alliance Between Nazi Germany and America's Most Powerful Corporation 
The crucial technology was a precursor to the computer, the IBM Hollerith punch card machine, which Black glimpsed on exhibit at the U.S. Holocaust Museum, inspiring his five-year, top-secret book project. The Hollerith was used to tabulate and alphabetize census data. Black says the Hollerith and its punch card data ("hole 3 signified homosexual ... hole 8 designated a Jew") was indispensable in rounding up prisoners, keeping the trains fully packed and on time, tallying the deaths, and organizing the entire war effort. Hitler's regime was fantastically, suicidally chaotic; could IBM have been the cause of its sole competence: mass-murdering civilians? Better scholars than I must sift through and appraise Black's mountainous evidence, but clearly the assessment is overdue.
The moral argument turns on one question: How much did IBM New York know about IBM Germany's work, and when? Black documents a scary game of brinksmanship orchestrated by IBM chief Watson, who walked a fine line between enraging U.S. officials and infuriating Hitler. He shamefully delayed returning the Nazi medal until forced to--and when he did return it, the Nazis almost kicked IBM and its crucial machines out of Germany. (Hitler was prone to self-defeating decisions, as demonstrated in How Hitler Could Have Won World War II.)
Black has created a must-read work of history. But it's also a fascinating business book examining the colliding influences of personality, morality, and cold strategic calculation. --Tim Appelo
Reviews
Even worse, by the time the war was in full swing, and the Nazis began the Holocaust the maniac of which I write, Tom Watson of IBM, saw no need to terminate IBM's business relationships with the Nazi governments, and, provided irreplaceable services in organizing the Holocaust. In France, where a courageous IBM employee refused to cooperate, the Nazis were "only" able to murder 25% of the Jews. Where IBM cooperated, as in the Netherlands, rates of 75% resulted. Life isn't fair; the brave Frenchman who refused to cooperate died at Dachau, the company that gladly cooperated wasn't punished. The horror, the horror.
Edwin Black has done a superb job of documenting (most of) this horror story in indisputable detail. Nevertheless I suspect that he doesn't tell the entire story, particularly when he claims that nobody guessed what was going on. Anyone who understands just how indispensable IBM's punch card machines were to the Allies during the war, "our ability to organise wouldn't have been remotely near what it was without them" to paraphrase one mathematician involved, must have wondered how the Germans were able to coordinate the logistics of their Blitzkrieg. Anyone in the punch card industry would have known of IBM's presence in Germany.
All in all this is a great book illustrating the banality of evil.
It is hard to believe that it took from the early 30's to 2001 before anyone, anywhere, put it all together. How could an American icon of business turn out to be a war criminal and go on to preside over, and build on to, a company which most of us used to consider as a proud example of American business ingenuity and integrity.
A shocking, sickening, and gut wrenching account of the most vile group of humans ever assembled, the Germans of the Third Reich, and how they could not possibly have achieved the sheer numbers of murders during the holocaust, had it not been for day to day involvement, and complete knowledge, of IBM and Thomas J. Watson.
I highly recommend this book.