December 10, 2024

1. IP
 A. IPSec
   FreeSWAN
   CIPE
 B. PPTP
   PPTP Client
   PopTop
 C. L2TPD
   L2TPD

2. TCP
 OpenVPN
 VTUN
 tinc

3. Application
 A. SSH
   Surf at work
   VPN Howto – SSH and PPP
 B. SSL
   SSL VPN
 C. Others
   Kaboodle

Links:
Google
VPN Labs
Linux VPN Client?
Intro to VPN – About
VPN Info
VPN – dtools
VPNC
FindVPN
VPN – CoreCom
Wikipedia