1. A computer-implemented method, comprising: determining a set of non-portable object classes of an application, the determining comprising: identifying a set of root object classes defined by the application; validating the root object classes, the validating comprising: adding to the set of non-portable object classes each of the root object classes that is not defined by the application, not defined by a shared optional package, and not one of a set of standard object classes; analyzing an executable version of the application to identify object classes referenced directly or indirectly by the root object classes, wherein said analyzing comprises parsing at least some of the executable version of the application and does not comprise executing the application; repeating the validating for each of the object classes referenced by the root object classes; generating a portability verification report for the application, wherein the portability verification report indicates that the application violates a portability criterion if the set of non-portable object classes is not empty.