Some language files exist twice: fr_FR_2.mo is an alternative version
made by another translator. The sole reason why one translation was made
the "default" version (xx_XX.mo) and another one the "alternative" 
version (xx_XX_w2.mo) is that the translator of the default version submitted
his version first. If you do not like the default xx_XX.mo, rename it
to xx_XX_alt.mo or something, and rename the alternative xx_XX_2.mo to 
xx_XX.mo to make it your default version.

For some languages it is not quite clear which locale should be used as
per http://codex.wordpress.org/WordPress_Localization
- Vietnamese could be vi or vi_VN
- Japanese could be ja or ja_JP
If the file names provided with the theme doesn't work, try changing the
file name to the other version (ja vs. ja_JP, etc.), and/or changing the 
WordPress locale to the file name. Usually the WordPress locale and theme 
translation file name should match.


For more info and updated translation files vsit
http://forum.bytesforall.com/showthread.php?t=82


Currently existing languages (This list is probably outdated, please check
the forum thread at the top of this file):

de_DE - Deutsch: <a href="http://www.lelei.de/">Christian Hans</a>

hu_HU.mo - Hungarian - Magyar: <a href="http://www.sakraft.hu/">FYGureout</a>

po_PO.mo - Portuguese: <a href="http://www.bergspot.com/">André Bergonse</a>

cz_CZ.mo - Czech: <a href="http://blog.rudice.cz/">Pepawo</a>

si_SI.mo - Slovenian: <a href="http://www.fama.eu/">Franci Humerca</a>

tr_TR.mo - Turkish: <a href="http://www.mentalmasturbasyon.com/">Mental Masturbasyon</a>

fr_FR.mo - French: <a href="http://tomne.free.fr/">Michael Zapata</a>

fr_FR_2.mo - French (Altern. Version): <a href="http://www.wolforg.eu/">Wolforg</a>

pl_PL.mo - Polish: <a href="http://agard.wordpress.com">Agard Khaardin</a>

nl_NL.mo - Dutch: Jos Tiel Groenestege

bg_BG.mo - Bulgarian: <a href="http://blogs.hostbg.biz/Veselin/">Veselin Dimitrov</a>

it_IT.mo - Italian: <a href="http://gidibao.net/">Gianni Diurno</a>

vi.mo - Vietnamese: <a href="http://www.anbinh.info/blog/">Teddy Bear</a> 
  (Depending on whether your core WordPress locale is vi_VN or vi you might 
  have to either change the Wordpress vi_VN.mo to vi.mo or change the Atahualpa 
  vi.mo to vi_VN.mo. They should be both either vi.mo or vi_VN.mo)
  
ja_JP.mo - Japanese: <a href="http://www.ounziw.com/">Fumito Mizuno</a>
  You may have to change this to ja.mo

ja_JP_2.mo - Japanese (Altern. Version): nasa9084
  You may have to change this to ja.mo
  
es_ES.mo - Spanish: <a href="http://aves.denordelta.com.ar/">Javier Vasquez</a>