User level (lightweight) TCP/IP stack with IPv6 support

 LWIPv6 is a user level TCP/IP stack with the following features:
 .
 Physical layer: ARP support, TUN/TAP/VDE drivers support.
 .
 Network layer: IP forwarding, fragmentation, NAT, IPv6 Stateless Address
 Autoconfiguration, Router Advertising support.
 .
 Transport layer: TCP: congestion control, RTT estimation, fast recovery, fast
 retransmit; UDP.
 .
 Berkeley Socket API: Protocol families PF_INET, PF_INET6, PF_PACKET, partial
 PF_NETLINK support; Socket types SOCK_STREAM, SOCK_DGRAM, SOCK_RAW support.
 .
 LWIPv6 is used, for instance, by a UMView module to support user level
 networking and configuration, usually together with VDE.
 .
 LWIPv6, along with UMView, is part of the View-OS project:
 http://wiki.virtualsquare.org