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 of 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 developed and distributed illegitimately in circumstances of copyright infringement or software piracy. Illegitimate key generators are typically programmed and distributed by software crackers in the warez scene. These keygens often play music (taking from the tradition of cracktros), which may include the genres dubstep, chiptunes, sampled loops or anything that the programmer desires. Chiptunes are often preferred due to their small size. Keygens can have artistic user interfaces or kept simple and display only a cracking group or cracker's logo.