The Agile Revolution in software development is software development catching up to the fact that it's a writerly art. All writers don't know where they're going or how they're going to express it when they start out. Neither do software developers. They can pretend by writing it the first time in a spec language and then coding it before checking the specification. That was when I was getting started the right way to write software. Now we think that IDs are for experimental writing and we should use formal specifications for our books. Well that's nuts. And what Agile did is say no this isn't wrong you have permission to do experimental writing and the IDE.