Linux Foundation updates kernel development study
Approximately 7,800 different developers at around 800 companies have contributed changes to the Linux kernel since Linux 2.6.11 was released in March 2005. Almost 18% of modifications were developed by volunteers who are known to contribute to Linux in their spare time; however, at least 75% were contributed by developers who make their living by working on Linux. These figures are based on the number of changes – this results in a one-line change counting the same as a large patch.
Red Hat employees contributed 11.9% of changes, followed by programmers employed by Novell (6.8%), Intel (6.2%) and IBM (6.1%). Whether the developers contribute in their spare time or through doing paid work was unclear for about 5% of changes. The figures are slightly different when only looking at the changes that have been introduced since version 2.6.36, which was released in October 2010: volunteers only produced 16% of changes, and Red Hat employees contributed just 10.7%. Next in line are Intel (7.2%) and Novell (4.3%), followed by the group of unknown developers (4.3%) and IBM (3.7%); Microsoft came in at the 21st place on this list, contributing 1% of changes.
This is one of several analyses the Linux Foundation has released in a document entitled "Linux Kernel Development: How Fast it is Going, Who is Doing It, What They are Doing, and Who is Sponsoring It". The current edition is the fourth white paper of its kind; like previous analyses (1, 2, 3), it was compiled by Jonathan Corbet (LWN.net), Greg Kroah-Hartman (Linux Foundation) and Amanda McPherson (Linux Foundation).
The study not only examines the sources of changes and the developer's employers, it also investigates various other aspects. It mentions several of the most important events that have occurred in the Linux kernel environment over the past year, including the switch to version number 3.0, the start of major ARM code revisions and the intrusion into kernel.org. The authors have also looked at the size and development time of the kernel versions that have been released in the past few years – many of the recent Linux kernels were developed in less than 70 days. Another analysis investigates which developers and companies review commits before they are passed on to Linus Torvalds.
The Linux Foundation has released the current study as part of the sixth annual Collaboration Summit, which is currently taking place in San Francisco. The technology consortium has also published a very simple and easy to understand video that explains how the Linux kernel is developed to those who aren't familiar with the Linux development process: