The IBM OS390 mainframe was running fine at AmerenUE's Callaway nuclear power plant—but executives sensed that the inflexibility of mainframe technology would position them poorly for the future. So they migrated and consolidated 50 mainframe applications to an infrastructure based primarily on the Windows Server® operating system, enabling them to decommission the Callaway mainframe. They rewrote small- and medium-sized applications using Microsoft® .NET-based tools and adopted more than 20 commercial, off-the-shelf applications, including the eB document management suite from Microsoft Gold Certified Partner Enterprise Informatics (formerly Spescom). Callaway gained the agility to respond to business needs faster and more effectively. It saves nearly U.S.$1 million annually in reduced personnel and licensing costs, and it gets the same reliability it enjoyed on the mainframe.