Expireware is a free software, comparable to shareware or freeware. Expireware has a certain expiration date, hence the name Expire, until which the software can be used and tested. After this expiration date, which is checked against the computer's system time, the software can no longer be accessed. A variant of Expireware expires after a certain number of calls. The aim of these measures is to persuade the customer to purchase a license or to buy the full version.