What's the Business Case for Microsoft and Open Source?

Friend of perl developers everywhere, Jeremy Zawodny, has an intriguing question: "If you had to explain to Microsoft why they should change their attitude toward Open Source, what would you say?" For more about this, read on... From Jeremy: "If you had to explain to Microsoft why they should change their attitude toward Open Source, what would you say? More to the point, how can Microsoft benefit from better supporting or even adopting Open Source in their business? (Replace IIS with Apache, for example.) Does it make sense for them? Are there ways that they can use Open Source as a competitive advantage without pissing off the Open Source community in the process? Which of their products would make sense on Open Source platforms? How can the Open Source community help Microsoft? Or is this a lost cause? IBM has made it work. Can Microsoft?

I ask these questions because I may have the chance to talk with folks at Microsoft about Open Source. And it only makes sense that I look to the community for input. So let's hear it. Flames won't help. Thoughtful answers and ideas very well could."