Described are systems and methods for upgrading a software program between sequential or non-sequential versions. An interface definition file of a first version of the software program is stored. The software program is upgraded from the first version to a second version. The second version of the software program is stored in the memory. A determination is made regarding the availability of a difference tool. The difference tool determines according to a static comparison one or more differences between the interface definition file of the first version and an interface definition file of the second version, and generates a results file that displays the determined differences.