OpenVPN

OpenVPN is a full-featured open source SSL VPN solution that accommodates a wide range of configurations, including remote access, site-to-site VPNs, Wi-Fi security, and enterprise-scale remote access solutions with load balancing, failover, and fine-grained access-controls. Starting with the fundamental premise that complexity is the enemy of security, OpenVPN offers a cost-effective, lightweight alternative to other VPN technologies that is well-targeted for the SME and enterprise markets.

OpenVPN is a portable user-space VPN solution that runs effectively on a wide range of hardware from routers to servers and operating systems from GNU/Linux to most flavours of MS Windows and Apple. Configurable installers for MS systems allow for easy, click and go deployments by the end-user. Unlike some VPN solutions, OpenVPN sets up reliable tunnels without problems through NAT and SLIRP (virtual machine) routers.

The donation page is http://openvpn.net/donate.html .