"The team studied Debian Linux, a free operating system
continuously being developed by more than 1,000 volunteers from
around the world. Developers create software packages, such as text
editors or music players, that are added to the system. Beginning
with 474 packages in 1996, Debian Linux has expanded to include
more than 18,000 packages today. The packages form an intricate
network, with some packages having greater connectivity than
others, as defined by how many other packages depend on a given
package.
""Open source offers a unique opportunity provided by the high
completeness of data concerning open source (thanks to the
disclosure policy of the open source terms of license)," lead
author Thomas Maillart of ETH Zürich told PhysOrg.com. "Debian
Linux allowed us to retrieve exhaustive information from several
years ago. Many other complex systems are not so well
'documented.'"
"As the researchers explain, the Linux network is constantly
changing: new packages enter, some disappear, and others gain or
lose connectivity. Yet throughout the 12 years, the distribution of
packages, as ranked by their number of incoming links from other
packages, has followed Zipf's law, with a few very popular packages
having much greater connectivity than most."