From: Jan Panteltje on
Wanted to test a Microchip ENC28J60 ethernet controller chip.
That chip is 3.3V and 5 V tolerant.
So decided to test on the PC par port first.
Ended up writing a complete UDP ARP subsystem in C,
this will add ethernet for next to nothing to anything that has an 8 bits port.
http://panteltje.com/panteltje/jppecat/

Those who know netcat will see I wrote a netcat clone on top of the UDP layer.

Version 0.3 is on the site, it has default gateway and netmask option added,
so it can work worldwide via a router.
Would you believe that was only 10 lines of extra code?