[..] we consider the design process as a recursive operation taking place in increments of, say, weeks. That is, after each increment, we aim at having a finished product [..]. In other words, we consider the product as always, from the very first few weeks onward, to be in the hands of users. A version of the product is always finished and available for use.

Now, how old is this quote? Certainly not more than ten years, that would have been my guess. Probably from the early XP days? Actually, the quote is from 1977’s august edition of IEEE Computer. Interesting, isn’t it?