Microsoft and the Linux Foundation have penned a joint letter to the American Law Institute, in opposition to its proposal to create an implied warranty that software goods ship with “no material defects”.

The odd coupling between the openista group and software multinational came about over a common beef the two parties had with the ALI.

In the letter, dated 14 May, Microsoft and the Linux Foundation asked the ALI “to delay adoption of its Principles of the Law of Software Contracts… to allow for wider consultation with affected parties, including developers and distributors of software.”

The proposals outlined by the ALI “interfere with the natural operation of open source licenses and commercial licenses as well by creating implied warranties that could result in a tremendous amount of unnecessary litigation, which would undermine the sharing of technology,” wrote Linux Foundation executive director Jim Zemlin.

Microsoft’s deputy general counsel Horacio Gutierrez, who in the past has accused the free and open source software community of violating no less than 235 Microsoft patents, preferred to highlight the bottom line in Redmond’s argument against the ALI’s principles.

"Microsoft and the Linux Foundation believe that certain provisions do not reflect existing law and could disrupt the well-functioning software market for businesses and consumers, as well as create uncertainty for software developers," he chimed yesterday.

Gutierrez also took the opportunity to reach out to the open source community, which in the past has given Microsoft and its locked down approach to software interoperability a frosty reception, at best.

"The mere fact that the Linux Foundation and Microsoft are joining forces may be viewed by some as remarkable, given that our differences receive far more public attention than when our interests converge," he noted.

"I hope that this represents just one of many opportunities to collaborate with the Linux Foundation and others going forward," said Gutierrez. "We have a lot more we can do together."

However, the tone was markedly different earlier this year when Microsoft threw a sueball at TomTom, which was the first of its kind against a company that implements the Linux kernel in its technology.

The two firms later settled the legal dispute in a five-year agreement that will see the GPS maker pay Microsoft for coverage under the five car navigation and three file management patents cited in the February suit brought by Redmond. ®