Open source licences hold up in court

Software developers who give away their code under an open source licence can sue for copyright infringement if that agreement is broken, according to a ruling in an American court.

The Artistic Licence that accompanies many open source projects demands that any use of the code is attributed, and that improvements and additions are released under the same terms so that the project can continue to grow.

Until now these licences have been unproven in court, but a US judge has ruled that developers can sue for breach of contract if they are infringed.

The ruling was issued in a court case brought against Matthew Katzer, who stood accused of developing a commercial application without attribution based upon the DecoderPro project hosted at SourceForge.

"Copyright holders who engage in open source licensing have the right to control the modification and distribution of copyrighted materials," said the court document outlining the ruling.

The decision is a boon for the open source community, which regularly sees free and open code appropriated for commercial projects. The court ruling makes it clear that the terms of the open source licence in use must be adhered to.

"For non-lawgeeks, this won't seem important. But trust me, this is huge," said Stanford Law Professor Larry Lessig in a blog post. "In non-technical terms, the Court has held that free licences set conditions on the use of copyrighted work. When you violate the condition, the licence disappears, meaning you're simply a copyright infringer."