The Collaborative software development model is a style of software development whose focus is on public availability and communication, usually via the Internet.
The software development model began widespread adoption with the Linux kernel in 1991.
It is the dominant model used in development of free software. It is very compatible with free software because free software projects publish the source code of any published programs, so they do not have the secrecy reason for hiding their communications and in-progress development.
Massive scale peer review of software changes is possible under the collaborative development model. This has been summarised by Raymond in what he terms Linus's Law: many eyeballs make all bugs shallow.
However, the extent that such peer review actually occurs is disputed .