OpenVPN is an easy-to-use, robust, and highly configurable VPN (Virtual
Private Network) daemon which can be used to securely link two or more
private networks using an encrypted tunnel over the internet.

With OpenVPN, you can:

* tunnel any IP subnetwork or virtual ethernet adapter over a single UDP
or TCP port,

* create cross-platform tunnels between any of the operating systems
supported by OpenVPN including Linux, Solaris, OpenBSD, FreeBSD, NetBSD,
Mac OS X, and Windows 2000/XP,

* use all of the encryption, authentication, and certification features
of the OpenSSL library to protect your private network traffic as it
transits the internet,

* use any cipher, key size, or HMAC digest (for datagram authentication)
supported by the OpenSSL library,

* choose between static-key based conventional encryption or
certificate-based public key encryption,

* use static, pre-shared keys or TLS-based dynamic key exchange,

* use real-time adaptive link compression and traffic-shaping to manage
link bandwidth utilization,

* tunnel networks whose public endpoints are dynamic such as DHCP or
dial-in clients,

* tunnel networks through connection-oriented stateful firewalls without
having to use explicit firewall rules,

* tunnel networks over NAT, and

* create secure ethernet bridges using virtual tap devices.