Novell isn't the only company that could be hurt by new license terms likely to be implemented by the group that polices open source software. In a regulatory filing, digital video recorder manufacturer TiVo warned that the newly revised General Public License could harm its business.

TiVo's set-top boxes run on the open source Linux operating system and incorporate GNU open source components. Its systems include features that limit Tivo's functionality if users attempt to modify its internal software.

Tivo hacking is becoming a popular way for users to work around the copyright protections that TiVo has added to its systems as part of its effort to build partnerships with content providers.

The forthcoming third version of the General Public License, however, would prohibit manufacturers of consumer appliances that use open source software from implementing technical measures designed to prevent user modifications.

According to the final draft of GPLv3, released Thursday by the Free Software Foundation (FSF), "When you convey a covered work, you waive any legal power to forbid circumvention of technical measures."

That has TiVo worried. "If the currently proposed version of GPLv3 is widely adopted, we may be unable to incorporate future enhancements to the GNU/Linux operating system into our software, which could adversely affect our business," TiVo warns.

The warning was contained within a 244-page financial report that TiVo filed with the Securities and Exchange Commission in April.

The FSF has said it expects GPLv3 to be published in its final form this summer.

In an essay accompanying the release of the final draft, FSF president Richard Stallman took specific aim at TiVo's digital rights management (DRM) policies in explaining the ban on anti-modification measures.

"The ban on tivoization applies to any product whose use by consumers, even occasionally, is to be expected," Stallman wrote.

"GPLv3 ensures you are free to remove the handcuffs. It doesn't forbid DRM, or any kind of feature. It places no limits on the substantive functionality you can add to a program, or remove from it. Rather, it makes sure that you are just as free to remove nasty features as the distributor of your copy was to add them," he continued.

"Tivoization is the way they deny you that freedom; to protect your freedom, GPLv3 forbids tivoization," wrote Stallman, who is known for his uncompromising views favoring free software.

Stallman, however, indicated that the ban does not apply to products meant to be used primarily in business environments.

TiVo officials were not immediately available for comment.

Last week, Novell warned that GPLv3 could disrupt its Linux distribution partnership with Microsoft. Among other things, the new rules would require Microsoft to abandon any patent claims on Linux users if it continues to distribute the open source software through the partnership.