Abstract
This research maintains that the open-source software (OSS) development model known as "bazaar model" is not only best one and cannot be always adopted. Especially, we use the concept of the modular architecture and the integral architecture which have been discussed in researches on product architecture of automobile, computer and so on. And we consider the impact of the OSS modularity on the collaboration mechanism of its development. As a result, we conclude that it is difficult that many developers collaborate one another when the OSS architecture is integral, even if many volunteers who intend to contribute to the development exist.
