What is Vocaloid? Vocaloid, quite simply, is a software that simulates singing. Each Vocaloid has a voice bank recorded by real people. Think of it as the most extreme auto-tune software in existence. It's become quite popular in Japan, to the point where there are even Vocaloid music tours. I'm going to cover the most popular/well-known Vocaloids, but currently there are 27 official Vocaloid products, with plans to release many many more. What is Nico Nico Douga? NND is a video-sharing site. It is very popular for releasing Vocaloid content, and the Vocaloid weekly charts use NND metrics to determine rankings. Most Vocaloid videos on YouTube are reprints from NND, and many will reference the original NND video URL in the format sm#######. What is MMD? MMD is Miku Miku Dance, which is a freeware commonly used to make videos of various Vocaloids. Most of the models and scenery are user-created, though the software comes with models for many of the older Vocaloids. Hatsune Miku If you've ever seen a Vocaloid before, it's probably Miku. There's currently two versions of Miku, Hatsune Miku (CV01) and Hatsune Miku Append, and a third version slated for release later this year. Miku is considered the most popular Vocaloid, and was largely responsible for the growth of the Vocaloid user base. Her software was much easier to use than previous products. Miku is also the base software for two popular spin-offs, Yowane Haku and Akita Neru. Kagamine Rin and Len Kagemine Rin and Len are packaged together, with separate voice banks recorded by the same voice actress. There is no canon relationship between them, but they are frequently depicted as twins. They are also occasionally depected as lovers, and less frequently, in some sort of suboordinate/superior relationship. Rin and Len have had three releases so far, with three more currently planned. Megurine Luka Luka's was the first Japanese Vocaloid to be able to handle English (and the second Vocaloid to do any English at all after Sweet Ann), and has competing popularity with Miku. There is currently only one version of Luka, with two more planned.