During the last half year the Sentiment classifier have been beta enabled for Spanish, French and Swedish. The test period has been very successful and we have decided to expand multi language support to more popular classifiers such as the Gender Analyzer, Mood and Myer Briggs classifiers.
Classifiers with multiple languages are have flags displayed like the icons above. From the GUI you can test them by clicking the flag first, from the API you simply add the language code (/es, /fr, /sv) to the request URL, for more information see the documentation.
The service is still in beta, as we still need to make sure it scales when more users start to use it. The API will probably not change.