What is "keygen"

n. (context computing English) A small program used to generate a key, such as a cryptographic key or a key used to unlock a trial version of software illegitimately.

A key generator (key-gen) is a computer program that generates a product licensing key, such as a serial number, necessary to activate for use a software application. Keygens may be legitimately distributed by software manufacturers for licensing software in commercial environments where software has been licensed in bulk for an entire site or enterprise, or they may be distributed illegitimately in circumstances of copyright infringement or software piracy. Illegitimate key generators are typically distributed by software crackers in the warez scene and demoscene. These keygens often play chiptunes in the background and have artistic user interfaces.