The Unisys mainframe systems trace their heritage to the first commercially available mainframes. The Unisys ClearPath Forward (CPF) Dorado (legacy Sperry 1100/2200) and Libra (legacy Burroughs A Series/Master Control Program) systems are full-featured mainframe operating environments. They can scale vertically to handle mission-critical workloads. These systems can be emulated, converted, or modernized into Azure. Azure offers similar or even improved performance characteristics and service-level agreement (SLA) metrics.

https://learn.microsoft.com/en-us/azure/architecture/example-scenario/mainframe/unisys-clearpath-forward-mainframe-rehost