Microsoft's core business model is not based on Open Source. But we recognize that today's technology users have diverse needs that neither a single vendor working alone, nor any one way to make software, are likely to meet. In this session, we will show how end users can benefit from a joint collaboration as well as from a healthy competition between Microsoft and the Open Source community. We would like also to explain why Interoperability is so important and how Open Source is influencing our own product development, from Windows Server 2008 to Windows Azure, our next generation cloud computing platform.