This is Japanese-Engrish =]
Lyrics are in hex code lol.
Vocaloid is "a singing synthesizer application software developed by the Yamaha Corporation that enables users to synthesize singing by just typing in lyrics and melody."
So simply anyone can produce vocaloid music by using the software and the singer.
And for the singing you have a number of voices you can choose from the 'Singing library' which is a pre-recorded voice like "Hatsune Miku", "Megurine Luka", "Kagamine Rin", "Meiko", "Kaito" etc. (These arent real people, they are virtualized characters) And these names are really famous and have their individual characteristics like given biographical information (age, weight etc), each of them has different emotion/attitude/behavior embedded. It gets right when you think of them as an Anime character basically.
I'm not all about Vocaloid but I do enjoy listening to some of them =D