Its interface is extremely simple. There's a box for the text you want to translate, the translated text, and the language selector.
It supports more than 30 different languages including English, French, Spanish, German, Chinese, Russian, Portuguese, etc.
goot also lets you add plugins to use different translators, bringing more possibilities, including new languages and other features.
Unzip the file and run the got.jar file with Sun Java 6 Runtime.