Synonymous.com

Lexiconer English Chinese Dictionary
English-Chinese and Chinese-English interfaces using the Linux Chinese/English dictionary database pyDict, written in Python/GTK. (Big5, GB)
www.lexiconer.com/

Chinese/English Talking Dictionary
YellowBridge’s CEDICT and Unihan interface, searchable by English, Pinyin with tone numbers or marks, Chinese character, or radical-stroke. Proprietary software required to hear pronunciation. (UTF-8)
www.yellowbridge.com/

Dr. Dict: English-Chinese Medical, Biological, and Technical Dictionary
Specialized online database of scientific terminology with over 420,000 entries. (GB)
www.drdict.com/

Mandarin Book Chinese-English Dictionary
Simple CEDICT and UNIHAN interface searchable by Pinyin, traditional character, or English, and with pronunciation sound files.
www.mandarinbook.info/

English-Chinese Dictionary
OK88’s online version of Linda Ng’s English to Chinese dictionary. (Big5, GIF)
www.okdaily.com/

Lin Yutang's Chinese-English Dictionary of Modern Usage
Chinese University of Hong Kong’s Web edition based upon the1972 dictionary with over 40,000 entries. Indexed by radical, Pinyin, and English, and searchable by full text or head character. (Big5)
humanum.arts.cuhk.edu.hk/

Online Chinese English Dictionary
Indra Kurniawan’s CEDICT and Unihan interface, searchable by English, Pinyin, Japanese, Cantonese, Chinese character, or radical-stroke. (UTF-8)
dictionary.kaide.net/

Chinese dictionary
Uses graphics files to display the characters.
www.zhongwen.com/

English to Chinese Online Dictionary
Online-dictionary.biz’s CEDICT server, English search only, one of seven language dictionaries. (UTF-8)
www.online-dictionary.biz/

Mandarin Planet Chinese-English Dictionary
This CEDICT interface, with over 34,000 entries, can be searched by traditional or simplified Chinese characters, Pinyin, or English. Audio pronunciation is available. (GB, Big5, or UTF-8)
www.mandarinplanet.com/