UTAU is a free singing synthesizer program that was developed to use wave files that could be put together to simulate singing. UTAU is best known for letting people create their own voice banks by the use of their own voice.
The UTAU voice banks are often personified into characters called UTAUloids. This became popular after Kasane Teto, a former VOCALOID joke character, became known as an UTAU.
UTAU isn't VOCALOID and shouldn't be confused with or tagged as such (and vice versa).
