[henrik_w]

The XP book was hugely important for me. I read Kent Beck's article on Extreme Programming in IEEE Software in October 1999, and got the book as soon as it came out. For the first time I saw a methodology that reflected how I actually liked to work. I hadn't done pair-programming then, but working in small increments, with lots of tests, rewriting etc - more agile in short. Previously, I wrote programs despite the methodology (like RUP, or company internal methodologies), but here was a system that actually helped. Truly revolutionary at the time.

[ollysb]

The strange thing is that this is how everyone begins to program you write a little code and get something working. Then you add a little more, reorganise things a little and keep going. It's a natural process that somehow gets trained out of us in CS courses. We're taught how to plan a whole system and them build it. Long running projects interacting with an infathomonable number of users put paid to that though. I think the thing extreme programming got most right is that software is about people. Telling the computer what to do is the easy bit. Figuring out what the users want them to do is the hard part.

[discreteevent]

The main thing for me is that its virtually impossible to build a complex system (essentially complex that is) without having good feedback and then adjusting the design to fit. That feedback comes from testing, review and the customer. The shorter the feedback cycle the quicker you settle on the target. The XP book helped spur this on in an age where a lot of people had lost the run of themselves. However these ideas were around and practiced since software development started:

http://www.craiglarman.com/wiki/downloads/misc/history-of-it...

And before that for other activities: "Plans are nothing; planning is everything." - Dwight D. Eisenhower

[henrik_w]

Exactly. You grow software. I really like this quote (by John Gall):

"A complex system that works is invariably found to have evolved from a simple system that worked."