Russian Word Monger offers an efficient way to learn the Russian language vocabulary. It will be given in Russian with its English translation and transcription. You can also listen to the pronunciation of every phrase. You can mark studied words to prevent them from reiteration.
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.
