Ignore them and they'll either go the hell away or spend some time fighting against each other and kill each other off.
I'm sure that they will NOT go away and I doubt that they will kill each other off. This is more of an evolutionary type struggle and not a physical combat. They are battling it out in the marketplace and one of the IDN solutions will evolve to the point where the market considers it clearly superior. This may be the IETF-blessed solution and it may not. One only has to browse through the RFC archives to see that RFC status is no guarantee that something will be widely adopted. Personally, I think that the Internet is too young and we have too little experience with multilingual naming to engineer an Internationalised Domain Naming solution that solves the problem once and for all. This means that we should be ready for more than one iteration to get to the solution. --Michael Dillon