Wikimedia projects support over 270 languages. This amazing global reach is powered by volunteers who translate not only the contents but also text used in MediaWiki so that localized wikis can be easily navigated and operated by users in their local language. Translatewiki.net is the amazing translation engine which not only supports Wikimedia projects but other open source projects. Siebrand and Nike are leading this translation platforms.
The user experience programs at Wikimedia Foundation is also benefited from translatewiki.net and translation volunteers. The usability beta has been completely translated into thirteen languages and twelve languages are 99% complete. These stats can be found at the translation completion status page for the usability extension by courtesy of GeardM.
The usability beta is planned to be switched to be the default interface in April. Additional translation boost for languages which are not fully translated will improve the usability of the new interface greatly.
GerardM had a great example of the interface in Nepali, whose localization is not complete, in his blog.
Translation help for such as Indonesian, Greek, Thai, Arabic, Hebrew, Italian, Sinhala, Korean and much more, are greatly appreciated.