I was excited to see that the Linux Foundation just released an update to their Linux kernel study. This study has some interesting insights into the work that goes into each revision of the kernel along with some information about the people and companies supporting this work.
For example, there are 4-5 kernel releases per year and recent releases have contained over 9000 changes (patches) per release, which breaks down to 4-6 changes to the kernel per hour. The most recent kernel in the study had over 11 million lines of code. This is a huge effort, especially for something that started off as a little hobby.
When you look at the people who contribute to the kernel, you see a mix of contributions from people whose companies sponsor their efforts and other people who contribute without any compensation. About 18% of the contributions come from people with no corporate affiliation, which means that no company is paying them to contribute to the Linux kernel, and another 7.6% of the contributions come from people whose corporate affiliations are unknown. While many of the people who contribute to the Linux kernel do so without any support from their employer, a significant number of people are contributing to the kernel as part of their day jobs.
The top five individual companies sponsoring Linux kernel contributions include:
- 12.3% Red Hat
- 7.6% IBM
- 7.6% Novell
- 5.3% Intel
- 2.4% Oracle
If you look just at recent contributions (changes since 2.6.24, which was released on 1/24/2008), you'll see some subtle changes in the percentages contributed by the top 5 companies:
- 12.0% Red Hat
- 6.3% IBM
- 6.1% Novell
- 6.0% Intel
- 3.1% Oracle
It's great to see Intel in the top five companies who support the Linux kernel by getting an increasing number of real people to roll up their sleeves and contribute code. You can get a link to the report from the Linux Foundation. I highly recommend reading the rest of the report, since I merely scratched the surface with a few interesting data points in this blog post.