It's not popular, but I don't see it as at all goofy. When I have a well-defined but difficult segment of an application to write, I whip out my literate-programming tools so I can get it right the first time, document the heck out of it, and be able to get back into its complexity if I ever need to change it. It's a fabulous, almost magically successful technique, even if I don't use it for most of the code I write.

I think of it as analogous in feeling and usage to how a musician practices a difficult passage slowly, with a metronome, perfecting it at gradually increasing speeds until they can play it perfectly at speed. It's tedious and time-consuming, so I tend only to use it when I feel the need, but when I do, I'm glad it's there.