Peg Solitaire is the CocoaHeads collaborative project, bringing Jeff Szuhay's Peg Solitaire program forward from the 1991-era classic Mac API into the land of Cocoa. Most of the early work done by MarkD. The narrative is basically the way MarkD builds a new small Cocoa project, but with each part captured.
Here are some notes on the various stages (the names are the CVS labels if you want to check out the code from source forge CVS, and webby version, sometimes a couple of hours out of date due to sourceforge policies). The project name is "PegSolitaire". Or you can download tarballs of the source. (most of the space consumed by the downloads are screen shots for the narratives)