The IUpgradeable interface allows module developers to apply code during install/upgrades based on the module version - this works in a similar fashion to DotNetNuke's upgrade based code.
The IUpgradeable interface includes a single method, UpgradeModule, which enables the module to execute custom business logic depending on the current version of the module being installed.
Public Interface IUpgradeable
Function UpgradeModule(ByVal Version As String) As String
UpgradeModule is called once for each script version included with the module. It is called only for script versions that are later than the version of the currently installed module.