Google Translate - Google's free service instantly translates words, phrases, and web pages between English and over 100 other languages.
Linguee - English Dictionary and Translation Search with 1,000,000,000 example sentences from human translators. Languages: English, German, French, Spanish, and Portuguese
Dictionary.com - Dictionary.com is the world’s leading digital dictionary. We provide millions of English definitions, spellings, audio pronunciations, example sentences, and word origins.
Spanish to English - Instant Spanish to English translation. Thousands words and phrases available!
Pootle - Multiple file formats.
BabelNet - The largest multilingual encyclopedic dictionary and semantic network