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

this package contains the files needed to compile applications that link lwipv6.