Over the past few weeks we've had a number of offers to translate the SilverStripe CMS into other languages which has been extremely gratifying.
Currently we don't have support for other languages, however it sounds like this is a feature we may need to fast track given the demand for a non English administration interface.
If you are able to assist translating SilverStripe into other languages, reply to this post, with the languages which you would be willing to translate for.
I'll get in touch with everyone who replies in the next few weeks about what needs to happen to get that ball rolling :-)