Is OpenVPN standards-compliant?
As a user-space VPN daemon, OpenVPN is compatible with SSL/TLS, RSA Certificates and X509 PKI, NAT, DHCP, and TUN/TAP virtual devices. OpenVPN is not compatible with IPSec, IKE, PPTP, or L2TP.
Can OpenVPN tunnel over a TCP connection?
Yes, starting with version 1.5.
Can I use a web browser as an OpenVPN client?
No. While OpenVPN uses the SSL/TLS protocol for security, OpenVPN is not a web application proxy. It is an OSI layer 2 or 3 full-mesh internetwork tunneling solution and requires that OpenVPN be installed on both client and server.
OpenVPN runs on:
OpenVPN runs on Linux, Windows XP/Vista/7 and higher, OpenBSD, FreeBSD, NetBSD, Mac OS X, and Solaris.