"Clue for linux (clue-dictionary-client) is an application for doing lookups in the dictionary files from Clue Norge ASA. The linux client itself is GPL, but the data are covered by the commercial license which you got when you bought the dictionaries from Clue Norge ASA. It's illegal to use this program with the Clue dictionaries if you do not have a license. You are not allowed to distribute the dictionaries with this program."
So if you own one or more of these dictionaries, now you can use them under Linux too. Cool!