It`s probably a CPAN module called Device::SerialPort;
Hello peter a,
Thanks for the big hint... I appreciate that..

I quickly browsed the net for this and found
http://www.cpan.org/.
But the problem with building the cpan modules from the tarball is that there are too many dependencies that is needed... luckily there is a faster way to install the cpan module Device::SerialPort into the plug.
I found this:
#apt-get update
#apt-get install libdevice-serialport-perl
Together with the following:
1. perl script from
http://www.bigsister.ch/zwave/zwave_s2. TrickleStar USB dongle
3. Leviton ZWave Light Dimmer
4. Light bulb
I was able to control a light bulb by issuing commands on the plug's console.
Yeah!... home automation is cool.
Also, thanks Tom Aeby! (the maker of the perl script)
