S3.Google Translator - this extension for Firefox browser make much easy visit of websites on foreign language.
The extension uses the Google translation public API http://translate.google.com/
and therefore it have more than 80 languages which you can use for translation.
Also, the extension able to auto-detect the language of the original text.
There are a lot of simple and complex extensions for Firefox browser but they all have same problem: when translating, the format of selected text is lost, while S3.Google Translator retains the HTML formatting of web pages.
I hope that this extension will be very useful for you.
Mozilla’s Pick of the Month: S3.Google Translatorhttps://blog.mozilla.org/addons/2013/11/01/november-featured-add-ons/