Untangle is the free & open source alternative to Sonicwall. In addition to the basics (Firewall, VPN, IPS & routing), Untangle makes it easier to block spam, spyware, viruses, phishing, porn, gambling, MySpace, Facebook, IM, peer-2-peer & much, much more. Untangle has been named the "Best Security Solution" – LinuxWorld 2007
Category: Opensource VPN
OpenVPN – OpenSource SSL VPN Solution
OpenVPN is a full-featured SSL VPN solution which can accomodate a wide range of configurations, including VPN client remote access, site-to-site VPN, WiFi security, and enterprise-scale remote access solutions with load balancing, failover, and fine-grained access-controls.