.it is the Internet country code top-level domain (ccTLD) for Italy. It's widely used in Italy.
Because "it" is also a word in English, it's commonly used to create domain hacks such as redd.it.
Any individual and company in Italy can register a .it domain name directly under the TLD. There are also other second-level domain extensions such as gov.it, edu.it, and province and region names under .it. There are too many second-level extensions under the .it TLD.
.IT domain extension ranks #16 among all domain extensions, and #10 among all country-code extensions (ccTLDs). Currently, there are 2.7 Million registered .it domain names. IIT - CNR is the registry of .it extension.
The oldest (still exists) .it domain name is informa.it, and it was registered on 29 January 1996.
The most popular .it domain name is redd.it. Its worldwide rank is 235.