ARTFL Project: French-English Dictionary: Bidirectional database of about 75,000 terms.
Basic Word List - English-French: Vocabulary for beginners. About 1000 entries.
Bilingual French-English Dictionary: Collaborative project hosted by Rennes University 1. General scope, bidirectional search capability, quiz for learners.
Cambridge Klett Compact, French-English: From Cambridge University Press, for learners. Also in print.
French Linguistics: One-way lookup (French-English) and downloadable educational games by Neil Coffey.
Semantic Atlas: Translation and synonym dictionary designed by the Lyon Institute for Cognitive Sciences (CNRS - Université Claude Bernard Lyon 1). It provides a geometric model for representing the meaning of words.
The Probert Encyclopaedia's English/French Dictionary: Multiple-page document of general scope. With bidirectional lookup, and plain translations.