The Free Software Foundation (FSF) issued a statement Friday claiming that a New Mexico-based Linux company has violated the GNU General Public License (GPL), by using a patent license to restrict distribution of its version of the open-source operating system.
Victor Yodaiken, chief executive officer of Finite State Machine Labs (FSMLabs) used the license to "impose restricted terms on distribution of a GPL-covered program," The FSF said in a statement. FSMLabs' version of Linux is called RTLinux.
The FSF opposes the use of software patents and believes they are a "harmful government policy of creating monopolies that restrict computer users," the group said in its statement. It also believes that the patent license violates the GPL of the Linux kernel. The GNU GPL states that any software incorporating source code that is already licensed under the GPL will itself become subject to the terms of the license. The GNU GPL also states that all improved versions of GPL software must be released as free software.
Yodaiken's patent covers "real-time interrupt handling using a software emulation layer for interrupt masking, so that interrupts can be prioritised," the FSF said. According to the FSF, the idea is not patentable because it has been used before.
The patent has been used to impose restrictive terms on a program covered by the GPL, and imposing them is a violation of the license, the FSF said. Because the FSF is not a copyright holder of Linux, it cannot enforce the GPL, but the organisation may choose to support efforts to invalidate the patent and uphold the GPL, it said.
Neither party could be reached for comment on the issue. The text of the patent license can be found at http://www.fsmlabs.com/PATENT.html