In a ruling Wednesday, the federal appeals court in Washington said that just because a software programmer gave his work away did not mean it could not be protected.
The decision legitimizes the use of commercial contracts for the distribution of computer software and digital artistic works for the public good. The court ruling also bolsters the open-source movement by easing the concerns of large organizations about relying on free software from hobbyists and hackers who have freely contributed time and energy without pay.
It also has implications for the Creative Commons license, a framework for modifying and sharing creative works that was developed in 2002 by Larry Lessig, a law professor at Stanford.
That license is now used widely by organizations like MIT for distributing courseware, and Wikipedia, the Web-based encyclopedia. In March, the rock band
The ambiguity facing open-source licensing has been one of the hurdles facing the movement, said Joichi Ito, the chief executive of Creative Commons.
"From a practical business perspective when big companies and their legal teams look at Creative Commons there are a number of questions," he said. "It's been one of the things their legal teams throw at us."
The appeals court decision reverses a San Francisco federal court ruling over the misappropriation of a software program by a company that publishes model train hobbyist software.
The free software, or open source, community has quarreled for several years with Matthew A. Katzer, a Portland, Ore., businessman who owns Kam Industries. Previously, Mr. Katzer has sued free software developers for patent infringement and the free software community has argued that he had failed to disclose earlier technology, known as prior art, in his patent filings.
A lawyer for Katzer did not return calls asking for comment.
In March 2006, Robert G. Jacobsen, a physics professor at the University of California, Berkeley, filed a lawsuit against Katzer claiming that his company was distributing a commercial software program that had taken software code from the Java Model Railroad Interface project and was redistributing the program without the credits required as part of the open-source license it was distributed under.
The decision to appeal the lower court ruling, which said that the terms of the open-source contract were overly broad, was intensely debated within the free software movement. Some open-source advocates had worried that a loss before the appeals court would have been a disaster for the community, which has grown as an economic force during the last quarter century.
"I was terrified that we would lose," Jacobsen said. "But I thought it was the right thing to do."
There has long been a link between model train hobbyists and the free software movement. During the 1950s, for example, hobbyists who worked on the wiring of the Massachusetts Institute of Technology model railroad club project were informally known as "hackers," according to Hackers: Heroes of the Computer Revolution by Steven Levy. The term evolved to include people who developed and programmed computers and who passionately believed that software codes should be freely shared.
Jacobsen said he believed that the court's ruling was significant for the free software movement because it had thrived not on monetary gain but on individual credit for contributions.
"We don't charge for this and so all we really get is credit," he said, adding that anyone is free to use and modify the programming instructions created by his group as long as they retain the credit and distribute them with the programmer's instructions.