Linux kernel community grows, but elite group remains

Viro has contributed 1,571 changes to the kernel, which sits at the core of the Linux operating system, over the past three years, according to a new report from the Linux Foundation. That's more than any other individual developer, the report states. In contrast, Torvalds, the kernel's creator and steward, contributed 495 changes. Viro couldn't be reached for comment about the report.

During the past three years, the top 10 individual developers have contributed nearly 15 percent of the changes to the kernel, while the top 30 developers have submitted 30 percent, the report states.

But this group of coding superstars sails atop a roiling sea of newer community members, notes Jim Zemlin, executive director of the Linux Foundation. Roughly 3,700 developers from more than 200 companies have contributed to the kernel since 2005, according to the report.

The statistic underscores the widespread penetration of Linux into enterprise computing. But the report was still necessary in light of lingering public perceptions, Zemlin said.

"I do think there continues to be groups of people out there who perceive open source and Linux as some kind of random hobbyist movement," he said. "It's amazing that after Linux is running the New York Stock Exchange, that people would still doubt it's ready for prime time. Yet, I hear it, in kind of mainstream conversations."

The report breaks up contributors into a number of categories.

The top-ranking one, with 13.9 percent of the kernel changes, contains developers performing work on their own time, with "no financial contribution happening from any company," according to the report.

Coming in second was the "unknown" category -- developers for whom a corporate affiliation couldn't be found -- with 12.9 percent. "With few exceptions, all of the people in this category have contributed 10 or fewer changes to the kernel over the past three years, yet the large number of these developers causes their total contribution to be quite high," the report noted.

Developers tied to companies and foundations ranked next, with Red Hat in the lead (11.2 percent), followed immediately by Novell (8.9 percent), IBM (8.3 percent), Intel (4.1 percent) and the Linux Foundation (3.5 percent) on the list of 30. A slew of other corporations round out the list with smaller contributions, such as Oracle (1.3) and Fujitsu (.5 percent).

"What we see here is that a small number of companies is responsible for a large portion of the total changes to the kernel. But there is a 'long tail' of companies which have made significant changes,'" the report said.

Zemlin suggested this is set to accelerate, given that many new products using Linux will hit the market in coming months: "Think about how many of those people will become kernel code contributors."

Despite all the activity, the kernel project is in no danger of being hijacked by particular corporate interests, he said: "The companies understand the principles of the development process and the rules by which people participate. They understand it is built on trusting relationships, both individually and from a corporate perspective."

Greg Kroah-Hartman, one of the report's authors and number 26 on the top 30 individual contributors' list, works on the kernel as part of his job at Novell but did it as a hobby prior to that, he said via e-mail last week.

Kroah-Hartman echoed Zemlin in discussing the kernel community's growth.

"If you look, there is no huge majority of a single company doing all of the work with no one else," he wrote. "It is spread out over a handful of very involved companies, and a large number of semi-involved companies. Because no one company controls it, everyone works together, which is a requirement in order to do this kind of development."

"Why wouldn't Linux be appealing to corporations and they support it?" he also noted. "When was it last considered 'grassroots?' Seriously, anyone who has had any glimmer of kernel experience has been instantly snapped up by corporations hiring them to do this kind of thing full time for a very long time now."