DeepDict can be used freely for a 2-week trial period with up to 10 daily look-ups. All you have to do is register with a login name and e-mail. Ordinary licenses come in 3 flavours:

Teaching & Research: This license applies to schools and universities. DeepDict data may be used in an educational context and published as excerpts in academic papers or teaching materials

Commercial standard: This license applies to individual commercial users, non-educational public institutions and companies, who use DeepDict as a kind of advanced on-line dictionary, but not for lexicography.

Commercial direct: This license applies to commercial users who publish printed or on-line dictionaries or provide lexicographic services to their customers.