Raymond distinguishes between two ways of managing a software project: the
traditional "Cathedral" way, and the novell "Bazaar" way.
In the Cathedral way, the software is developed by a limited number of
developers, released only when being very stable, and maintained without
too much help from the outside.
In the Bazaar way, the software is released very often (often in a buggy
state), tasks are delegated and contributions from the outside are welcome
and often.
ESR attributes the "invention" of the Bazaar way to Linus Torvalds who used
it to develop the Linux kernel, a core component of a critical system - the
GNU/Linux operating system. (albeit acknowledges that it was used before for
other projects)
In "the Cathedral and the Bazaar" he documents his experiences in developing
and maintaining his own project Bazaar-style: the
fetchmail
POP-retrieval system.