A platform is provided to allow the developer to log into a subscriber's computer system by using the credential of the developer or the subscriber to view and to debug at least a portion of executable code that is used by the subscriber. The executable code used by the subscriber may be part of managed package code, at least portions of which are customized for various subscribers. Cooperative debugging may be provided between developer and subscriber with lifting of code encapsulation for the developer in the subscriber implementation. The developer and the subscriber may be granted debugging licenses each authorizing a limited number of debugging sessions, and each debugging session run by the developer may be counted against the debugging license of either the developer or the subscriber. Debugging licenses may be transferred between the developer and the subscriber.