The PHP Application Distribution Licensing System (PADL) generates keys that control the distribution of PHP applications according to a license. It generates license strings that can bind PHP applications to specific servers, confine execution to a limited time period, or restrict execution to a single server. The time limiting uses a start period (and a given start offset to allow for time discrepancies) and an expiry date if required. When validating a key it is possible to optionally make applications dial home to check the license key on your own server. It is also possible to encrypt additional information into the license key.
