OpenVPN is a full-featured SSL VPN solution which can accomodate a wide range of configurations, including remote access, site-to-site VPNs, WiFi security, and enterprise-scale remote access solutions with load balancing, failover, and fine-grained access-controls (articles) (examples) (security overview) (non-english languages).
What's new in this version:
OpenVPN 2.3 is the first release with major new functionality from the OpenVPN community, change log can be found HERE