Vocaloid was developed by Yamaha and is now available in Spanish, Chinese, and Korean. In addition to these 3 new languages, it also still includes English and Japanese. You can make each character sing almost anything you'd like simply by typing in the words and choosing a note.
They will have a trial version available for download between January 28th and February 14th, 2013. Go to this link for the trial: http://www.ssw.co.jp/megpoid-trial
More libraries of singers are also being created by third parties from other voice actors/actresses.
Here is the complete history of Vocaloid: