Apache::File does two things. First, it provides an object-oriented interface to file handles, similar to Perl's standard IO::File class. While the Apache::File module does not provide all the functionality of IO::File, its methods are approximately twice as fast as the equivalent IO::File methods. Secondly, when you use Apache::File, it adds to the Apache class several new methods that provide support for handling files under the HTTP/1.1 protocol.
Supplied with the mod_perl distribution. See the module manpage for more information.