I own a wiki called "Tous aux Balkans" (in French it's a play of word, meaning "Everybody to the Balkans") http://tousauxbalkans.jexiste.fr
It contains folkloric song lyrics and music notes (scores) from Central/Eastern Europe, the Balkans, and more (Turkey, Armenia, Israel...). They are categorized by country or area, rhythm (there are plenty of typical rhythms in thoses musics ! I love that !), style/genre and dance, sometimes also by featured instrument, and artist who sing/play that music.
I created this wiki to organize audio, video, lyrics and scores I collected here and there, on various websites, in workshops I take part (I play accordion and sing), exchanged with friends... So I can share what I learned in workshop with other friends, and together we can help each other, one translating, another telling what kind of dance it is...
Technically... It's default lang is french, some message are translated into english when user change it's prefered lang, but some names (especially categories) are still in French.
An article is made of song lyrics, translitteration if needed (for greek, cyrilllic alphabet), translation (french, english, german), medias (pdf, midi, view/play/transpos/.../printable score with a mac/win plug-in, mp3, video), and sometimes explanations (notes), chord grid.
I wrote several extension for this wiki, I published them on mediawiki.org : - youtube video - google video - mp3 (plays a mp3 using a very light flash swf) and other not published yet : - dailymotion video - draw a chord grid (for example here : http://tousauxbalkans.jexiste.fr/All_of_me ) - ...
Enjoy !