At the moment I am working in the translation of planeshift to the Castilian and must say that almost I have it completes, still lack some adjustments, but this is the list of files that (so far) I have touched:
/data/gui/buddy.xml
/data/gui/charcreate.xml
/data/gui/chardescwindow.xml
/data/gui/charpick.xml
/data/gui/chatmenu.xml
/data/gui/chat.xml
/data/gui/childhood.xml
/data/gui/configchatfilter.xml
/data/gui/configchat.xml
/data/gui/configdetails.xml
/data/gui/configtityinter.xml
/data/gui/configentitylabels.xml
/data/gui/configkeys.xml
/data/gui/configmouse.xml
/data/gui/configpvp.xml
/data/gui/configsound.xml
/data/gui/configwindow.xml
/data/gui/containerdesc.xml
/data/gui/credits_config.xml
/data/gui/detailwindow.xml
/data/gui/eedit.xml
/data/gui/exchange.xml
/data/gui/filenavigation.xml
/data/gui/fingering.xml
/data/gui/gmaddeditaction.xml
/data/gui/gmguiwindow.xml
/data/gui/gmspawn.xml
/data/gui/group.xml
/data/gui/guildwindow.xml
/data/gui/helpwindow.xml
/data/gui/ignorewindow.xml
/data/gui/infowindow.xml
/data/gui/interact.xml
/data/gui/inventory.xml
/data/gui/itemdesc.xml
/data/gui/lifeevents.xml
/data/gui/loginwindow.xml
/data/gui/loot.xml
/data/gui/merchant.xml
/data/gui/ok.xml
/data/gui/parents.xml
/data/gui/paths.xml
/data/gui/paws_generic.xml
/data/gui/petitiongm.xml
/data/gui/petition.xml
/data/gui/questnotebook.xml
/data/gui/questrewardwindow.xml
/data/gui/quitinfo.xml
/data/gui/readbook.xml
/data/gui/shortcutwindow.xml
/data/gui/skillwindow.xml
/data/gui/smallinventory.xml
/data/gui/spellcancelwindow.xml
/data/gui/spellwindow.xml
/data/gui/styles.xml
/data/gui/summary.xml
/data/gui/widgetconfigwindow.xml
/data/gui/yesno.xml
/data/gui/zodiacs.xml (almost)
/art/skins/base/client_base.zip/backdrop/splash17.jpg
/art/apps.zip/popup17.png
/data/help.xml (almost)
If anyone can test it, download (unofficialy) at:
http://catarsys.com/projectes/planeshift/patch_castellano/planeshift_castilian_patch.tar.bz2(if you are a windows user, use winrar to uncompress it)
Here was some images of the changes:
capture 1 capture 2