Device::ParallelPort is a Perl API that allows low level access to the parallel port of most computers. It does this by using a number of drivers, which can be customized and added to, including Linux (direct and parport), Win32, Script, Dummy, and more. It also contains a number of direct access devices including an example printer and a relay controller card.
TapeChanger::MTX is a module to manipulate a tape library using the 'mtx' tape library program. It is meant to work with a simple shell/Perl script to load and unload tapes as appropriate, and to provide an interface for more complicated programs to do the same. It comes with a few basic scripts to use much of the functionality of the module.