OpenOffice.org Monday called Microsoft's assertion that its open source application suite violates 45 of its patents "a desperate act."

"It's just hard to put into credible terms," said Louis Suarez-Potts, a community manager for OpenOffice.org and seven-year veteran of the all-volunteer group. "I don't understand what motivated Microsoft to risk so much with a position that can only serve to alienate [enterprise] customers, as well as those millions of people who use Linux."

In an interview with Fortune posted on the magazine's Web site Sunday, Brad Smith, Microsoft's general counsel, spelled out the company's position. During the interview, Smith claimed that OpenOffice.org, the open source alternative to Microsoft's own Office suite, violates nearly four dozen patents. Smith did not specify the patents Microsoft believes have been violated by the application collection, nor did a follow-up statement issued by a Microsoft spokesman Monday.

OpenOffice, which is available in editions for both Windows and Linux, can be downloaded and used for free. A version written for Apple's Mac OS X Aqua interface should reach beta testing later this year. Microsoft Office 2007, meanwhile, comes in versions for Windows and Mac OS X, and is priced starting at $149.

"This is an extraordinary and desperate act," said Suarez-Potts, who works for the Canadian-based Collaborative Network Technologies. "I think it will backfire. Microsoft's using a shotgun against open source."

Suarez-Potts saw evidence of the scattershot approach in Microsoft's focus on GPLv3, version 3 of the Free Software Foundation's General Public License. A Microsoft spokesman today said: "The latest draft of the GPLv3 attempts to tear down the bridge between proprietary and open source technology that Microsoft has worked to build with the industry and customers."

But OpenOffice doesn't even use the GPL license, Suarez-Potts noted. "We use the LGPL (GNU Lesser General Public License)."

Previously, the only head-butting between Microsoft and OpenOffice.org has been over document formats, with the former pushing its Open XML and the latter promoting the open source ODF (Open Document Format).

"Incredible and amazing, those are the words I have for this," concluded Suarez-Potts.