This module implements asynchronous I/O using whatever means your operating system supports. Asynchronous means that operations that can normally block your program (e.g. reading from disk) will be done asynchronously: the operation will still block, but you can do something else in the meantime. This is extremely useful for programs that need to stay interactive even when doing heavy I/O (GUI programs, high performance network servers etc.), but can also be used to easily do operations in parallel that are normally done sequentially, e.g. stat'ing many files, which is much faster on a RAID volume or over NFS when you do a number of stat operations concurrently. While most of this works on all types of file descriptors (for example sockets), using these functions on file descriptors that support nonblocking operation (again, sockets, pipes etc.) is very inefficient or might not work (aio_read fails on sockets/pipes/fifos). Use an event loop for that (such as the Event module): IO::AIO will naturally fit into such an event loop itself. WWW: http://search.cpan.org/dist/IO-AIO/