Bubble Translate is an application that makes translation to more than 90 languages quite easy. All you need to do is select the text, press the combination of buttons, and get the result as a translated text. The transcription will be displayed automatically in a scalable pop-up window.
One World Dictionary by Ascendo is a leading multilingual reference tool for Apple desktops.
InstantTranslate makes it really easy to translate a selection of text in the application you are working in from one language to another language.
