Cathedrals vs Bazaars

With the continuing phenomena of open source software, a new system of developement has emerged.  This new system is what Raymond compares to a bazaar, where people from all over the world come together and collectivly collaborate and contribute to the developement of software.  Classically, software would be developed by a smaller group of individuals and would normally be commissioned by an overseeing company who would own the software upon its completion.
The classic approach to software developement will continue to dominate the field and is also the explanation to the sucess of open source software.  The classic approach to software developement has the major advantage of unity and a shared vision.  The most difficult part of building and maintaining software is to develope a mental model of the system.  This mental model needs to be the same between all the developers so that they can collectively build the software.  In open source developement maintaining this mental model becomes difficult because each participating developer brings their own ideas of what and how this software should perform.  In those extremely sucessful open source projects we see that this same classic model of building is still mostly followed, where the large majority of the project is built by a smaller group of individuals who hold and maintain that mental model.