Microsoft provides a Translator API that allows you to translate text from one language into another. It provides up to 1000 transactions/month for free. Google also provides a translation API, however has recently removed their free tier. One the projects I am working on needed the ability to translate text, so I wrote a node.js module for the Microsoft Translator API, which you can find more about at github.com/nanek/mstranslator.
The API itself provides a good set of languages to choose from and it also can provide the audio of the word being spoken.