strongSwan
strongSwan is an Open Source IPsec-based VPN solution for Linux and other UNIX based operating systems implementing both the IKEv1 and IKEv2 key exchange protocols.
IPsec-Tools is a port of KAME's IPsec utilities to the Linux-2.6 IPsec implementation. It supports NetBSD and FreeBSD as well.
ipsectools is a port of kame's ipsec utilities to the linux2.6 ipsec implementation. it supports netbsd and freebsd as well.
contents:
libipsec library with pf_key implementation.setkey tool to manipulate and dump the kernel security policy database (spd) and security association database (sad).racoon internet key exchange (ike) daemon for automatically keying ipsec connections.racoonctl a shellbased control tool for racoon
vpn virtual-private-network