PinYin displays PinYin (phonetic symbol of chinese word) of text selection. Please refer to "Read Me" before use it. The package contains source code. The program comes with CountCharacter, which displays word count of text selection of any Cocoa app via Finder's Context menu.
InstantTranslate makes it really easy to translate a selection of text in the application you are working in from one language to another language.
One World Dictionary by Ascendo is a leading multilingual reference tool for Apple desktops.