[jrogers65]

The application could "phone home" occasionally to check up on the status of the license. Should the business close, an override code could be provided (and fulfilment of this could be a contractual obligation).

Applications written in interpreted languages can usually be secured with tools built for the purpose (e.g. ZendGuard for PHP). Compiled languages do not have this problem in the first place.

[mooism2]

How do you enforce contractual obligations against a business that no longer exists?

[jrogers65]

Have a contract directly with the owners, I guess.