http://www.transparent.com/learn-spanish/proficiency-test.html

Spanish-English dictionaries

Bab.la

http://en.bab.la/dictionary/english-spanish/

Dictzone

http://dictzone.com/english-spanish-dictionary/

Dictionarist

http://www.dictionarist.com

LangToLang

http://www.langtolang.com

SpanishDICT.com

http://spanishdict.com

Freedict

http://www.freedict.com/onldict/spa.html

Freelang

http://www.freelang.net/online/spanish.php

Tomísimo

http://www.tomisimo.org

Babylon

http://dictionary.babylon.com/spanish

Diccionarios.com*

http://www.diccionarios.com

Word Magic

http://www.wordmagicsoft.com/dictionary

Spanish-English Translation Dictionary

http://education.yahoo.com/reference/dict_en_es/

English to Spanish dictionary

http://www.spanishhabitat.com/learn-spanish

Diccionario de Inglés-Español - Universidad de Oviedo

http://tradu.scig.uniovi.es/esp.html

English-Spanish / Spanish-English Dictionary

http://www.v7w.com/cgi-bin/es