This paper was improved by conversations with a large number of people who helped debug it. Particular thanks to Jeff Dutky <[email protected]>, who suggested the ``debugging is parallelizable'' formulation, and helped develop the analysis that proceeds from it. Also to Nancy Lebovitz <[email protected]> for her suggestion that I emulate Weinberg by quoting Kropotkin. Perceptive criticisms also came from Joan Eslinger <[email protected]> and Marty Franz <[email protected]> of the General Technics list. I'm grateful to the members of PLUG, the Philadelphia Linux User's group, for providing the first test audience for the first public version of this paper. Finally, Linus Torvalds's comments were helpful and his early endorsement very encouraging.