More open-source companies should be asking the U.S. Patent & Trademark Office to re-examine patents that may pose a threat to them, as a cheaper, sometimes more suitable alternative to waging a patent lawsuit, said Van Lindberg, an attorney with Haynes and Boone LLP, who spoke at Infoworld's Open Source Business Conference in San Francisco.

Fears about patent litigation have plagued both open-source companies and their customers, and stem from patent trolls as well as competitors. Microsoft, for example, has claimed that Linux may violate hundreds of its patents. It is currently suing GPS maker TomTom, partly over TomTom's use of the Linux kernel in its products.

Filing a re-examination request involves arguing to the USPTO that a patent should not have been granted in the first place, often because the technology was too obvious or because prior art, or previous examples of the technology, existed. Some open-source groups are using this method already, such as the Electronic Frontier Foundation with its . But the strategy is underutilized by the open-source community, Lindberg said.

"This is not a widely used technique among open-source companies, but commercial (proprietary) companies have become very enamored of it," he said.

Enterprises that depend heavily on open-source software might also benefit from requesting re-examination of patents that could impinge on it, Lindberg added.