Mandriva has followed in footsteps of Red Hat and Ubuntu in refusing to become a part of Microsoft's Linux patent protection plan.

Microsoft is trying to improve the interoperability of its software with open source alternatives, but continues to insist that it should be compensated for patents which it claims are violated by open source software.

Novell, Xandros and Linspire have already signed Linux patent licensing agreements with the Redmond giant.

Francois Bancilhon, chief executive at Mandriva, said on a company blog: "As far as intellectual property is concerned, we are, to say the least, not great fans of software patents and of the current patent system which we consider counterproductive for the industry as a whole.

"We also believe what we see and, up to now, there has been absolutely no hard evidence from any of the FUD propagators that Linux and open source applications are in breach of any patents."

Microsoft claimed in May that it had identified 235 patents violated by open source applications, but declined to identify any of the individual patents.

"We do not believe that it is necessary for us to get protection from Microsoft to do our job or to pay protection money to anyone," added Bancilhon.

Mandriva released Corporate Desktop 4.0 last week, the latest version of its enterprise-dedicated workstation.