Microsoft is an elephant that needs to be turned to stop it trampling the open source community, according to a vocal critic of the software giant's approach to software patents.

Speaking at the annual event, one of the lead developers for the Samba Team and Google employee, Jeremy Allison, described Microsoft as a real threat to the open source community.

"We have a system that is absolutely free that we can do anything with, so why are we so obsessed with picking on Microsoft?" Allison asked the audience. "Shouldn't we leave the elephant alone and stop poking it with sticks? Well, the problem is they aren't going to leave us alone."

Allison was quick to point out that his comments at the address are his own views and not those of his employer. In December 2006, Allison, a famed open source proponent, resigned his position at Novell to join Google in protest over the company's Linux/Windows interoperability deal with Microsoft.

In comments published at the time, Allison called Novell's deal with Microsoft "a mistake... [that] will be damaging to Novell's success in the future." He said that even if the deal, which involved Novell paying Microsoft for patents, did not violate the GNU General Public License (GPL), it violated "the intent of the GPL".

Just over three years later, Allison maintains the same threat to the GPL and the wider open source community remains. In his presentation, streamed from the website, Allison said despite some changes to Microsoft's personnel the company continued to refer to GPL Linux implementations as "infestations".

"Which kind of fits me as I always thought of myself as the cockroach in the wall when I started," he joked.

"But it is really not a sign of a company that is peacefully coexisting, adopting free software, trying to make money out of it like, for example, IBM or Google for that matter."

While acknowledging that many within Microsoft genuinely support free software, Allison went on to say the vendor has its own internal battles between business units that make it hard for outsiders to predict its actions.

"Microsoft is often compared to the Star Trek icon 'The Borg'. You have this wonderful little Patrick Stewart icon with his Borg headgear on whenever you have Microsoft on a Slashdot story," he said referring to the popular science fiction series and IT website. "I actually think that is completely wrong. We are the Borg, we really are. We integrate anyone's code, we can absorb code, we can take it, modify it, put it out there, re-purpose it. We are wonderful integrators of everyone's technology. But we are much friendlier."

The presentation moved on to looking at the historical view of Microsoft's engagement with open source, including the "Halloween" memos by Eric Raymond, before touching on three case studies which show how the vendor poses a threat to the GPL license: The OOXML standard; attempts to "corrupt" the open Internet; and the Tom Tom lawsuit.

In November 2008, the International Organization for Standardization (ISO) published the specification for a Microsoft-created file format, Office Open XML (OOXML), which caused bitter debate during its path to become an international standard.

OOXML was opposed by many on the grounds it was unnecessary, as software makers could use OpenDocument Format (ODF), a less complicated office software format that was already an international standard.

Allison contends the OOXML case shows the lengths Microsoft will go to in order to create lock-in, where consumers are forced to buy software or hardware from one vendor or its partners and freedom of choice is restricted.

"One of the worst things that happened out of that, [is that the ISO] which was previously respected by people that didn't know it so well, became absolutely despised," he said. "There are some countries now thinking of pulling out [of ISO] because it is simply not worth participating in a process that is so obviously corrupted."

However, the result was followed by two European Commission antitrust probes into Microsoft's behaviour which led to a settlement where the software giant had to offer customers a choice of internet browsers. The second probe into Microsoft's limiting of file format choices in its Office productivity suite also led to the vendor changing track. In the end, the ODF and other non-proprietary formats were offered to consumers to fend off European Union (EU) antitrust regulators and block massive fines.

For Allison, Microsoft's actions in both cases are symbolic of its distaste for free software principles and its efforts to maintain a stranglehold on much of the desktop market.

In the second case study, Allison argued Microsoft had tried to corrupt the open Internet by, among other things: Refusing to follow HTML standards and creating Internet Explorer-only websites, pushing its Windows-only media format, aiming to make ActiveX the only way to develop applications and trying to replace Java with .Net.

"This is still ongoing. Firefox broke the dam on this. Users that have no interest in PC software, no interest in anything but Windows, they know to click on the little red Firefox icon to be safe," he said, also acknowledging the rise of Flash.

"The reason it was much harder for them to win, though, should go to Apache. When you control the client and the server it is easier to tie them together so tightly... it is very hard for anyone else to get a toe hold. But with the web they never controlled the server marketplace."

In the long term, Allison claims Microsoft will fail on this front. But the vendor's pursuit of software patents poses a threat, he said, as evidenced when it brought a suit against TomTom allegeding infringement of eight of its patents, including three for the implementation of the Linux kernel, in February last year.

Although the two companies settled the suit a month later with Tom Tom agreeing to pay royalties, Allison said it was the first attempt to attack free software through patents.

"It was a shot across the bow of every Linux vendor," he said, adding "patents are still a monstrous threat".

"All of its strategies have failed to prevent the spread of free software and patents have the wonderful benefit to Microsoft and other companies of being completely incompatible with the GPL but they are still not addressed by [other licences] BSD or MIT and then if people produce code using them it can be used by Microsoft.

"So you see this especially in the appliance market where Microsoft will go to a company, off the record as this is never ever done in public, and say 'this product you have there, shame if someone brought a patent suit. So you have two options you can re-architect, here is Windows, or the other thing is why don't you give us a cut on all the free software you are using?'. It is an attempt to create the work that we do, into a Microsoft revenue stream. I don't know about you but that really pisses me off."

The use of cross licences, like that used in the Novell and Microsoft deal that led to Allison quitting his job, he said, manufactures "walled gardens" that split the open source community. Those inside the garden are safe while those outside must fend for themselves.

The solution? Ignore the threat.

"This is the most effective strategy we have. Keep our eyes on the prize, we keep doing this [free software development] and we will end up with a world where, yes, there may be more proprietary gardens but we can ignore them by creating our own content, creating our own software and creating our own hardware. Let's build the world that we want to see," he said.

Alternatively, corral it through transparency and accountability.

"The only other thing we can do is trying to build a fence around the elephant."