IBM has successfully executed a Linux and open source strategy that allows it to leverage the capabilities of its IBM Power Systems and IBM System z mainframes with modern software solutions. This IDC White Paper is based on research data collected at a dozen customer sites in the United States, Canada, and Europe, all with mixed server platforms, to find the technical and business outcomes from deploying cross-platform Linux solutions on IBM servers. This paper presents the key findings of a return on investment (ROI) analysis that was conducted by IDC at these customer sites.