MicroTCP: a minimal TCP/IP stack
MicroTCP is a TCP/IP network stack I started building as a learning exercise while attending the Computer Networking course at the Universita degli Studi di Napoli Federico II. It's just a hobby project and is intended to just be a minimal, yet complete, implementation.
At this moment MicroTCP implements ARP (RFC 826, complete), IPv4 (no fragmentation), ICMP (minimum necessary to reply to pings) and TCP (complete but not stress-tested). Note that complete" should not be intended as fully compliant" but just as a measure of progress on all of the major features. For instance, it's complete enough to handle HTTP traffic on a local network.
People like this usually end up writing a simple operating system, so it's interesting to see a TCP/IP stack instead. While clearly a hobby project, small, portable TCP/IP stacks can potentially be useful for very specific use cases, like bringing connectivity to ancient operating systems or other small hobby projects.