For more information, see the Wikipedia article... :)
I was surprised to not find any of them in avatars for SL, even in slx, even in japanese-only-sims stores... So i decided to make my own collection of them... Using the best semi-open-source anime-style avatar system ever, of course : Unreal :p
Here's the little descriptions of the avatars i made so far. Maybe there will be more to come :)
WINDOWS ME-TAN
This av have a very very simple design for a start : non-primed skirt, not tons of new textures... But this av have a feature completely made for it :
There's two chest ribbons in the package. And one of them is scripted. When you click the warning icon on it, it triggers an error function that makes appear a Windows error box at random times, with the lethal and well-known "ding" sound!!! (click a second time the icon to stop it)
WINDOWS XP-TAN
XP-tan was quickly made, i admit. The hairs are freebies i customised for the av and the arms things aren't as pretty as i'd wanted (i'm still a noob for sculpt building) but at least, i added something fun (very very fun if you use Emerald Viewer and that you enabled the breast physics option ;) )
When you wear the chichiyuke attachment and that you say "chichi" in the chat, your av (and others around if they wear the same device :p ) will bounce happily. It makes a very boin~ boin~ effect. And XP-tan is definitely into that thing, seriously :p (just watch the XP-tan videos in youtube, you'll see :p ) Bon~kyu, Booooon~ <3
WINDOWS 2000-TAN
I couldn't make Me-tan and XP-tan without doing 2K-tan! :p That one was a pain to make but i'm happy of the result :) She have a shared folder to read in the pack and only the glasses are freebies i modded. Enuff said :p
WINDOWS 3.11-TAN
3.11-tan is my personal favourite. She's just like a cute moe loli with a lil dominant side...hem well... :p That one was average to make but i enjoyed building her alot ^^ (often i wonder if i won't make some additional contents for this av someday :p ) She have a DOSkitty included that she carries when worn (on the left hand)
Maybe more to come soon :) And maybe i'll make a special pack including all of those avs in one, plus some additionnal contents (but without the Unreal parts. Must support Unreal avatars :p )