CKEditor is the plugin for quick test translation using the specialized services.

If you use the service Yandex Translate API translations are provided by a browser directly referring to the server Yandex. Google Translate API and Bing Translate API are also supported, but for using them your web server must support PHP.

The plugin has toolbar icon and popup menu item for immediate translation (shortcut can be used), also it has button for calling settings dialog and a button quick for reversing translation direction.

CKEditor Translator using screenshot
CKEditor Translator settings screenshot