Because it is also the English word it, and many words end with -it, it is commonly used in the construction of domain hackdomain names.
There are a number of reserved second-level domain names, for example domain names like italy.it or other names that are referring to geographical regions of Italy.
gov.it is the official governmental domain, and its use is increasing rapidly.
edu.it domain has been investigated, but its proposal was never formalized.
domains in the form comune.<locality>.<province>.it and comune.<locality>.it are reserved to Italian municipalities.
domains in the form provincia.<province>.it are reserved to Italian provinces.
domains in the form regione.<region>.it are reserved to Italian regions.