Adam Dunkels writes: "Inspired by the Twitter-sized program that crashes Mac OS X, I just wrote a really, really rudimentary IP stack called twIP, small enough to fit in a Twitter tweet. Although twIP is very far away from a real IP stack, it can do the first task of any IP stack: respond to pings. The entire source code can be found in this 128 characters long tweet. For those who are interested in low-level network programming, a code walkthrough with instructions on how to run the code under FreeBSD is available here. The FAQ: Q: why? A: for fun."