ENUM crawler: searches the e164.arpa namespace, and provides information how many NAPTR recrods are found in which country
IETF ENUM working group: The working group that standardizes ENUM and Enumservices
Austria (+43): enum.at
Czech Republic (+420): nic.cz
Germany (+44): DENIC
Romania (+40): enum.ro
United Kingdom (+44): UKEC
Poland (+48): dns.pl
Sweden (+46): IIS.se
Netherlands (+31): enuminnederland.nl (dutch)
Ireland (+353): ienum
(note - this list is not complete)