Comment Structured Programming (Score 1) 624
Even if it's somehow outdated (and no longer in print), every single program we write today is highly influenced by "Structured Programming" by Edsger Wybe Dijkstra, C. A. R. Hoare and Ole-Johan Dahl. Before this book, programs used to be a mess of spaghetti code and the familiar constructs like if-then-else or while loops did not exist.