That -apart from being a brilliant idea- seems to be easy to replicate in open source software. Replicate not in being compatible but as a different system altogether. Or has that already happened?
I also know of at least 2 other open source alternatives (what3ducks and what3fucks).
After playing a bit with their interface I can't really tell if they're successful but it does seem like it would be relatively complicated to come up with such a word list in many languages. That being said, it could probably be crowdsourced.