Microsoft loses Custom XML patent battle, again -

Microsoft has lost out again, for now, on the i4i Custom XML patent case which it requested to have reexamined by the U.S. Patent and Trademark Office and just got turned down.

Canadian firm i4i hasn't been pleased with how Microsoft has been using its Custom XML technology. The company sued Microsoft for willful infringement of its 5,787,449 patent back in March 2007.  Late last year Microsoft had been forced to remove Custom XML as part of Office, and was forced to hand over in excess of $290 million to i4i for infringing its patent. It went so far as to release a patch for Word 2003 through to Office 2007 to get rid of support for it.

But Microsoft kept challenging and challenging and requesting reexaminations. Its latest attempt to re-open old wounds has just been openly rejected according by the patent office, says i4i.

In a statement, i4i bigwig Loudon Owen said: "This is a very material step in our litigation against Microsoft. Put simply: i4i's patent is clearly and unequivocally valid. Even though Microsoft attacked i4i's patent claims with its full arsenal, the Patent Office agreed with i4i."

Despite Microsoft's sustained dismal record with this patent, director of public affairs Kevin Kutz told ZDNet: "We are disappointed, but there still remain important matters of patent law at stake, and we are considering our options to get them addressed, including a petition to the Supreme Court."

A Google search for i4i will bring up the autosuggest of 'i4i xml patent,' to give you an idea of how drawn out the battle has become. We think Microsoft should stop trying to claw back Custom XML - it's clear to us who has won this one.