In 1992 or so I suggested to an IBM person (Stan Smith), who was doing a master’s thesis under me at MIT, that he write his thesis comparing mainframe and PC software development. So he compared IBM and Fujitsu with Microsoft and Lotus, and got an interview at Microsoft, and I went with him there. When I heard the story of how Microsoft was developing software, I immediately knew this was very, very different from the waterfall world of software development that I had learned. Almost all the principles of agile development— Microsoft was doing back then. They just didn’t call it that at the time. So I immediately pitched a book to Microsoft, which eventually had to be approved by Bill Gates, which he did. I co-authored it with a professor of computer science, Richard Selby, because Stan went back to IBM. [Cusumano and Selby published the book, Microsoft Secrets, in 1995.] TCS: So what did you learn about the ways that Microsoft developed software in the 1990s? Cusumano: Since this interview is about lean and agile management approaches, I think you’ll find this interesting: Almost all the principles of agile development—Microsoft was doing back then. They just didn’t call it that at the time.