Widespread Linux Practice May Violate License; Study Addresses Loadable Kernel Modules, Called ``the Key to the Use of Linux in Embedded Systems''.

NORFOLK, Va. -- A common practice among embedded Linux developers almost certainly violates the Linux license, according to research conducted by software attorneys Jay Michaelson and Christopher Holst. Wasabi Systems Inc., a leading provider of embedded operating systems, today released a white paper entitled Closed-Source Loadable Kernel Modules Violate the GPL, which is the second in a series of white papers focusing on the myths and facts about open source licensing.

The latest white paper discusses the issue of Loadable Kernel Modules (LKMs), a method commonly used by Linux developers to circumvent the requirement that modified Linux code be shared with the public. Although Michaelson notes that there are many legitimate uses of LKMs, the code they contain would otherwise be part of the kernel and compiled along with it. In that case, the source code to these LKMs would have to be made public according to the terms of Linux's license, the GNU General Public License (GPL). By dynamically loading the code later, developers claim that it is not part of the GPL-covered kernel - a claim refuted by Michaelson and Holst.

"The trouble is that the GPL specifically includes 'derivative works' as part of the software covered by the license -- and LKMs are almost certainly derivative works of the kernel," says Michaelson, a noted and widely published expert on software licensing. "What that means is that this widespread practice almost certainly violates the license."

In the white paper, Michaelson contends that the reason the GPL has not been enforced in this area is that the Free Software Foundation (FSF), the non-profit organization that generally enforces the license, has mixed motives. "On the one hand, the Free Software Foundation wants to ensure compliance with the GPL," says Michaelson. "But on the other, they also want to ensure the success of Linux."

Michaelson believes that the risk for OEMs is not that the FSF will suddenly change its collective mind, but that other parties might have a different set of interests. "There are hundreds of copyright holders in the Linux world, and all it takes is one enterprising hacker to sue," Michaelson points out, adding that individual programmers have successfully compelled the release of code in the past. He goes on to say, "The current situation is essentially 'a Gentlemen's Agreement' that, like all such arrangements, is inherently unstable. As the FSF itself says, the only way to comply with the Linux license is to release your code to the public. These workarounds just don't hold water."

The white paper can be found today at www.WasabiSystems.com/gpl. As part of an educational campaign focused on the GPL, additional white papers, presentations and seminars will be made available.