A staggered execution environment is provided to safely execute an application program against software failures. In an embodiment, the staggered execution environment includes one or more probe virtual machines that execute various portions of an application program and an execution virtual machine that executes the same application program within a time delay behind the probe virtual machines. A virtualization supervisor coordinates the execution of the application program on one or more probe virtual machines. The probe virtual machines are used to detect and correct software failures prior to the execution virtual machine encountering them. The virtualization supervisor embargos output data in order to ensure that erroneous data is not released which may adversely affect external processes.