The Icann blog answered that question back in 2009, far more than I realized. I wonder what the count is now?

I got started wondering about how many TLD's existed because of the DNS SEC changes that begin tomorrow when they begin sending extended DNSSEC signature data in response to DNS queries - I've been told that as long as mn DNS resolver is not setting the DO (DNSSEC OK) bit in the request then I should be okay which is good because my initial tests indicate that my configuration is not up to handling the extended headers. Anyway, if anyone is curious enough to want to run the RIPE analysis for themselves you can get it here http://labs.ripe.net/content/testing-yo ... ize-issues and if you want more technical details on the "DO" (DNSSEC OK) bit settings then you can read about it here: http://www.ietf.org/rfc/rfc3225.txt