A Linux programmer reported a new victory in a German court Thursday in enforcing the General Public License, which governs countless projects in the free and open-source software realms.

A Munich district court on Tuesday issued a preliminary injunction barring Fortinet, a maker of multipurpose security devices, from distributing products that include a Linux component called "initrd" that Harald Welte helped write.

In addition to being a Linux programmer, Welte runs an operation called the GPL Violations project that attempts to encourage companies shipping products incorporating GPL software to abide by the license terms. The license lets anyone use GPL software in products without paying a fee, but it requires that they provide the underlying source code for the GPL components when they ship such a product.

The case highlights the ease with which open-source software can spread across the computing industry--but also the growing pains that companies face as they adjust to new legal concepts underlying the collaborative programming approach.

Fortinet, based in Sunnyvale, Calif., said in a statement it's addressing the issue but is surprised that Welte resorted to legal action.