1. A computer-implemented method comprising: identifying a first version of a virtualized application comprising a first read-only virtualization sublayer, the first read-only virtualization sublayer comprising a base state of the first version of the virtualized application; identifying a second version of the virtualized application comprising a second read-only virtualization sublayer, the second read-only virtualization sublayer comprising a base state of the second version of the virtualized application; determining a difference between the first read-only virtualization sublayer and the second read-only virtualization sublayer; using the difference to create a patch configured to update an instance of the first version of the virtualized application to an instance of the second version of the virtualized application.