Dicewaregen is simple perl script that generates Diceware dictionaries, that
can be used to create passphrases.

Dicewaregen relies on aspell, to make wordlist. Once you have wordlist you can
create Diceware dictionary. You can make few wordlists using different
languages, merge them and then make Diceware dictionary.

More info about Diceware: http://world.std.com/~reinhold/diceware.html