This stand-alone VPN client is not supported with Mac OS X 10.8 (Mountain Lion). Other versions of Mac OS X are similar to be configured, however there might be minor different on UIs. On this instruction, every screen-shots are taken on Mac OS X Mountain Lion. This tutorial will guide you how to set up OpenVPN Client on Mac OS X.Viscosity is an OpenVPN client with intuitive interface offering complete configuration of OpenVPN connections on Mac OS. Download Viscosity (Mac OS 10.7 or later is required).Step-by-step Guide to Setting Up OpenVPN on Mac OS X Step 1: Download one of the VPNBook OpenVPN certificate bundles Step 2: Open the downloaded OpenVPN certificate bundle folder Step 3: Download and install Tunnelblick OpenVPN Client Step 4: Launch Tunnelblick OpenVPN Client and click 'OpenVPN Configuration(s)' Step 5: Click 'I have configuration files' button.

Here is an instruction how to connect to a VPN Gate Public VPN Relay Server by using L2TP/IPsec VPN Client which is built-in on Mac OS X. Initial configurations (only once at the first time)