Microsoft and Novell today are marking the third anniversary of what was, at the time it was announced, a surprising business and technical agreement bridging proprietary and open source software. The companies say they have signed up more than 475 joint customers under their partnership, which aims to make it easier to run Windows Server and SUSE Linux more smoothly together. That's up from about 200 a year ago.

The agreement caused a big stir because of a provision in which each company promised not to sue the other's customers over patent-infringement claims stemming from their use of Windows or Linux. The provision is viewed by many in the open-source community as implicitly supporting Microsoft's allegation that Linux and other open-source programs violate its intellectual property.

It's still controversial in open-source circles, of course. But Susan Heystee, a Novell vice president, said today that, among customers, at least, any initial controversy has largely subsided.

Heystee comments during a media briefing today at the Society for Information Management's annual SIMposium national convention in Seattle, after I asked whether the companies might consider dropping the patent provision from future versions of their agreement. Even if the patent protections have prompted some customers to work with Microsoft and Novell, my theory was that the two companies might try to attract additional customers by dumping what has been the most controversial aspect of their agreement.

"It was controversial at the very beginning," Heystee said. "It is far from that today. I think we could have done a better job as Novell communicating that aspect of the partnership to the open-source community. But also recognizing that, at the time we signed that partnership, we were not partners, we were major competitors in the market. This was a big shift of the companies' philosophy and direction in terms of working together on interop. It was a new agenda, and people weren't sure what the results would be.

She continued, "Over the last three years, the IP peace of mind has been an element of the partnership that has been well-received by customers, and has not been controversial in the last couple years at all. It's really just become accepted as part of the program. Will it be part of our part of our partnership (in the future)? I think the core elements that have made us successful, we should look to those to stay part of the partnership going forward. What that looks like in the end, we'll have to see based on the discussions we're having, but I would expect that both of us would want to keep the pieces that have been really successful."

The companies are now entering the fourth year of the original five-year agreement. Asked if they're already working to extend the deal beyond the initial term, Microsoft general manager Ted MacLean didn't provide any specifics but said the companies in general are "constantly exploring how to continue working together."