Though the processes sound similar, the scope and details each is emphasizing are different. Spolsky: "feature" Fried: "app" Suppose either is designing Gree

Though the processes sound similar, the scope and details each is emphasizing are different. Spolsky: "feature" Fried: "app" Suppose either is designing GreenfieldGloryApp - he might start with a one-page vision statement. He might then make some very high level mock-ups of scenarios. Maybe they would even be done in HTML. This is where they diverge: At this point 37signals would start building. Fog Creek would iterate 'specs' many times further by drilling down to feature or feature-set level functional specs. Each feature-level spec would start with a vision statement and then be fleshed out with mocks and "detailed descriptions".