Cygnus Systems, a small Indiana-based software company has sued IT giants Google, Apple and Microsoft claiming it holds the patent to a common file preview feature that was used without permission by the three companies in many of their software products.

The feature subject of the controversy, common in many operating systems and software, is a preview tool that allows applications to show the file content without the user having to actually open it. According to Cygnus Apple, Inc. infringes the company's copyright by making use of the feature in its OS X operating system (in its Finder and Cover Flow feature); Microsoft also has a similar preview feature in its Windows Vista and Internet Explorer 8; Google and its Chrome Web browser also allow users to preview files in a way that is thought to be in breach of Cygnus' intellectual property.

Matt McAndrews, a partner with the Niro, Scavone, Haller & Niro, law firm which is representing Cygnus, told PCWorld.com that, while only three companies were sued at this time, further legal action will be taken on a number of other software products once (and if) these first companies will lose in court. "[Apple, Google and Microsoft] were a logical starting place for us [but] we've identified many other potentially infringing products that we're investigating," McAndrews said.

Cygnus applied for its patent in 2001, long before some of the best-known software — Internet browsers in particular — decided to integrate this feature in their code, but the patent was only granted in March of this year. Gregory Swartz, Cygnus' owner a

nd president, developed the technology laid out in the patent while working on IT consulting projects, and the company is now looking for a royalty fee as well as a court ruling preventing further infringment and retroactive payment going back to the beginning of the copyright infringment. The lawsuit was filed in federal court in Arizona, where Swartz resides, McAndrews said.

The complaint does however contain a few discrepancies, for instance when it claims that Google infringed the patent by "making, using, selling, and offering for sale Google’s Chrome web browser", while the software is downloadable for free for Windows XP and Vista from the Google website.

US patent 7,346,850 (System and method for iconic software environment management) describes "a method and system for storing, navigating, and accessing files within an operating system through the use of a graphical thumbnail representing the video display of the active document within the active application."

If the court were to approve Cygnus' request, this would have deep consequences on a very wide range of software, Internet browsers in particular. As we said above, Google Chrome and Microsoft's next version of Internet Explorer would have to drop the feature, but even Apple's Safari and the popular Opera Browser would have to do without the preview feature. Incidentally, Apple is also currently using the file preview feature on the iPhone. For each of these applications (and many more), the software houses would then have to choose between paying an usage fee and just dropping the feature from their products.

Google, Apple and Microsoft didn't release any official statements to answer the copyright infringment allegations, but a response is expected from them in the next few days.