In the latest news from the tech world's ongoing global hunt to find someone to sue over/deal with on patents, Microsoft has signed a licensing agreement with Casio.

The "broad, multiyear" contract, which neither party will put a price to, will help protect Casio devices that use Linux. While Linux is supposed to be open source, Microsoft has claimed since 2007 that more than 235 of its patents are violated by the project.

In the last four years, the software giant has been quietly threatening legal action for any Linux-using company that refuses to sign patent deals with it. Amazon, Novell, Linspire, TurboLinux and Xandros have all put their X on the dotted line. Others, like satnav maker TomTom, ended up in court, but eventually settled.

Microsoft has also used the Linux-related patents, among others, to target Google's Android, already succeeding in getting HTC, Acer, Viewsonic and two small hardware manufacturers – Onkyo and Velocity Micro – into licensing agreements.

It is clear that Microsoft is prepared to go legal when thwarted, having previously sued Motorola, Barnes & Noble, Inventec and Foxconn International over Android devices. But Redmond continues to couch the whole thing as happy tech companies helping each other, with corporate VP and deputy general counsel of the Intellectual Property Group at Microsoft Horacio Gutierrez saying in a canned statement that the Casio deal was "an extension of the long-standing relationship between the two companies".

“We’re pleased to reach an agreement and to see continued recognition of the value of our patent portfolio, particularly as it relates to operating systems,” he added. ®