I was reading the ThoughtWorks blogs and found a neat reference to Craig Larman’s keynote speech at Agile India 2006. Larman discussed the oft-repeated statement that agile is not suited to large defence projects, but countered from Sapolsky’s 1972 book on the history of the Polaris system, that “critical path analysis and PERT charts were used as a smokescreen to placate senior management while engineers got on with their iterative development process”. (Quoting the blog entry, not the original book.)
Here’s a further link to a paper he co-wrote in 2003 which chronicles iterative development going back into the 1930s and something very like XP popping up in 1957.