An Open-Source Free Cross-platform Multi-protocol VPN Program,
as an academic project from University of Tsukuba.
SoftEther VPN runs on Windows, Linux, Mac, FreeBSD and Solaris.
SoftEther VPN supports most of widely-used VPN protocols
including SSL-VPN, OpenVPN, IPsec, L2TP, MS-SSTP, L2TPv3 and EtherIP.
http://www.softether.org/5-download/history
http://www.softether.org/4-docs
mailto:softether-vpn-security@softether.org