1. A method for supporting the execution of a multicomponent software application (MCSA) in a virtual computer system, the method comprising: obtaining information about the MCSA, the information including resource requirements of individual components of the MCSA and performance objectives of at least some of the individual components; obtaining information about computing resources of multiple virtual machines (VMs) in the virtual computer system; using computer software to determine an allocation of the computing resources among the multiple VMs in which the multiple components of the MCSA are to execute, the determination of the allocation being based on the information about the MCSA and the information about the computing resources of the VMs; monitoring performance of the MCSA during execution of the multiple components, the monitoring being specific to the performance objectives of at least some of the individual components of the MCSA; using computer software to automatically adjust the allocation of the MCSA computing resources among the VMs in which the components of the MCSA execute based on the monitoring that is specific to the performance objectives of at least some of the individual components; determining if additional physical resources have been added to the virtual computer system; and in response to additional physical resources being added to the virtual computer system, using computer software to automatically adjust allocation of the additional physical resources among the VMs in which components of the MCSA execute; wherein automatically adjusting the allocation is implemented without migrating any VM from the physical computer on which the VM executes; and wherein the MCSA comprises a first set of components and a nested MCSA, the first set of components executing on a first set of VMs, the nested MCSA comprising a second set of components executing on a second set of VMs, wherein automatically adjusting the allocation comprises modifying a first resource pool associated with the MCSA and modifying a second resource pool within the first resource pool and associated with the second set of VMs, based on the modification to the first resource pool.