Software Freedom Law Center is again seeking a test case of the provisions of the GPLv2. It's filed suit against two firms, High-Gain Antennas and Xterasys Corp. for not disclosing the code included in their antenna and signal booster devices.

Both firms embed the BusyBox tools and utilities that are frequently used to create wireless and set-top box products. BusyBox is produced by independent developers Erik Andersen and Rob Landley under GPLv2. Dan Ravicher, legal director of the center, said his non-profit organization tries to resolve differences with commercial companies to bring them into compliance with the GPL. "If they are unwilling to work with us, then our only choice is to go to court," he said in a statement announcing the suits.

Xterasys produces broadband and Wi-Fi boosters, Ethernet cards, and Bluetooth transmitters. The SFLC announcement didn't name the products in which BusyBox is used. High-Gain produces multi-directional antennas and signal detection devices for wide and local area networks.

The Software Freedom Law Center previously challenged the use of BusyBox by Monsoon Multimedia for its use of BusyBox in a set of products sold directly to consumers by Best Buy, Fry's Electronics and CompUSA. They were also in products resold by Intel, Microsoft, Panasonic, Nokia, HP, Dell, Siemens and Toshiba.

That case was settled out of court Oct. 30, with Monsoon paying an undisclosed sum to the plaintiffs and agreeing to make its modifications of the code available to other developers.

The two suits, filed Nov. 19, are the second and third issued on behalf of the GPL in the U.S. So far, no GPL case has gone through the courts in the U.S.

The GPL requires an adopter of GPL code to publish to the public or "give back" to the developer community any changes or modifications to GPL code. GPLv3 was issued at the end of June with provisions written more expressly to ban the practice of embedding GPL code in a device without disclosing the changes made to it. Richard Stallman, head of the Free Software Foundation which issues the GPL license, said the practice amounted to the "Tivo-ization" of the GPL, or the undermining of its intent to keep code public.

The Software Freedom Law Center makes legal resources available to free software developers to defend their work. It is headed by Columbia law professor Eben Moglen.