Online dictionary

English-Chinese dictionary
http://www.onlinedict.com/ 顔元叔教授主編網路 英英/英漢辭典
http://www.dreye.com/tw/ 譯點通線上字典
http://www.okdaily.com/go/svc/ecdict.html English-Chinese Dictionary

English-English dictionary
http://dictionary.cambridge.org/ Cambridge dictionaries online
http://www.m-w.com/ Merriam-Webster On-Line
http://www.ldoceonline.com/index.html Longman dictionary of Contemporary English online

Chinese-English dictionary
http://www.ksjh.ttct.edu.tw/dict.htm 教育部英漢/漢英線上電子字典
http://www.1390.com.tw/free/dic_ee.htm 1390
http://humanum.arts.cuhk.edu.hk/Lexis/Lindict/ 林語堂當代漢英詞典電子版