What Is UTAU?
UTAU is a Japanese singing synthesizer application created by Ameya/Ayame. This program is similar to the Vocaloid software, with the difference that it is shareware instead of being released under third party licensing... UTAU has the ability to use wave files provided by the user, so that a singing voice can be synthesized by introducing song lyrics and melody. (From Wikipedia)
A look at the UTAU GUI
STUDIO OGIEN creates its own line of UTAU, refered to collectively as OGIENOIDs. Our line boasts numerous voices with unique pitches, appends and (soon) bilingual voices. OGIENOIDs are free to use, but we do require a purchase of a commercial license if profit is being made from their voices/characters ($5).