Openswan is an implementation of IPsec for Linux. It supports kernels 2.0, 2.2, 2.4 and 2.6, and runs on many different platforms, including x86, x86_64, ia64, MIPS and ARM.

KVpnc is a KDE frontend for various VPN clients. It supports Cisco VPN (vpnc, vpnclient (a proprietary client from Cisco)), IPSec (FreeS/WAN, Openswan, strongSwan, racoon), PPTP (pptpclient), OpenVPN, L2TP over IPSec (l2tpd, xl2ltpd) (usable with Fre