[About Algol 60] Due credit must be paid to the genius of the designers of ALGOL 60 who included recursion in their language and enabled me to descri… - Tony Hoare

The most important property of a program is whether it accomplishes the intentions of its user.

Programming languages on the whole are very much more complicated than they used to be: object orientation, inheritance, and other features are still not really being thought through from the point of view of a coherent and scientifically well-based discipline or a theory of correctness. My original postulate, which I have been pursuing as a scientist all my life, is that one uses the criteria of correctness as a means of converging on a decent programming language design—one which doesn’t set traps for its users, and ones in which the different components of the program correspond clearly to different components of its specification, so you can reason compositionally about it. [...] The tools, including the compiler, have to be based on some theory of what it means to write a correct program.

I have learned more from my failures than can ever be revealed in the cold print of a scientific article. [...] [Failures] are much more fun to hear about afterwards; they are not so funny at the time.