Inside every large program is a small program struggling to get out.

There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult.

Here is a language so far ahead of its time, that it was not only an improvement on its predecessors, but also on nearly all its successors.

I was eventually persuaded of the need to design programming notations so as to maximize the number of errors which cannot be made, or if made, can be reliably detected at compile time.

The job of formal methods is to elucidate the assumptions upon which formal correctness depends.

Some problems are better evaded than solved.

I couldn't resist the temptation to put in a null reference, simply because it was so easy to implement. This has led to innumerable errors, vulnerabilities, and system crashes, which have probably caused a billion dollars of pain and damage in the last forty years.