Experimental trials with enc28j60 ethernet chip and tuxgraphics TCP/IP stack.
Uses the tuxgraphics library version 5.2 with a small modification.
Also uses protothreads for psuedo multithreading: http://dunkels.com/adam/pt/
Hardware used for this example(s): http://kehribar.me/hardware/ethernetGateway
CoAP library is coming from: https://github.com/1248/microcoap