Some other IO modules don't belong to the perl core but can be loaded as well if they have been installed from CPAN. You can discover which ones exist by searching for "^IO::" on http://search.cpan.org.
For more information on any of these modules, please see its respective documentation.
=head1 DEPRECATED
use IO; # loads all the modules listed below
The loaded modules are IO::Handle, IO::Seekable, IO::File, IO::Pipe, IO::Socket, IO::Dir. You should instead explicitly import the IO modules you want.