LWN.net has an article (subscriber only until March 1st) on who wrote the current release of the Linux kernel, 2.6.20. The author analyzes the code repository to see who submitted changes and what company they work for. Here are the conclusions:

The end result of all this is that a number of the widely-expressed opinions about kernel development turn out to be true. There really are thousands of developers – at least, almost 2,000 who put in at least one patch over the course of the last year. Linus Torvalds is directly responsible for a very small portion of the code which makes it into the kernel. Contemporary kernel development is spread out among a broad group of people, most of whom are paid for the work they do. Overall, the picture is of a broad-based and well-supported development community.

The top contributing companies are:

Unknown: 19%

Red Hat: 12.8%

None: 11.0%

IBM: 7.3%

Other stats that caught my eye: Novell with 3.4%, Intel 3.4%, Sony with 2.4%, Nokia 1.6%.

The figures should not be relied on too much (note the large “Unknown” category) but it is still interesting. Contrary to a myth still sometimes peddled, Linux is not primarily the work of hobbyists in back bedrooms or students pulling all-nighters; but nor is it wholly taken over by the usual commercial suspects. I think these are healthy indicators.

Don Dodge has more extracts and commentary.