Seems that Freescale provides a GPL open source stack (I didn't investigate that tought)
http://blogs.freescale.com/2011/08/03/t ... d-systems/ (http://blogs.freescale.com/2011/08/03/there%E2%80%99s-a-stack-for-that-fnet-makes-tcpip-protocol-available-to-embedded-systems/)
You can download it from the project page: http://fnet.sourceforge.net/ (http://fnet.sourceforge.net/)
Nice. They have pretty fat chips, I bet it is a linux derivative. I'll post this up.