> My feeling is that most problems have already been solved - but we write code because it's quicker to write code than discover it.

Fantastic quote.

> In a wiki if you click on a link and no page exists you are prompted to write some text - we could make a similar thing to develop programs.

This reminds me of my early days of programming where I managed to build (relatively) complex apps/games in Delphi with only a murky understanding of even the basics of programming.

I had only a vague notion of what a function/procedure was, for example, but being able to drag a button onto the canvas, double-clicking it, and seeing a text field where I could write code and refer to other elements made perfect sense.