VPN server+client

I would like to see a free vpn server/client application for both the Win/Linux OSes. An easy to install and setup (as are most of your products) to allow secure encrypted traffic via a LAN, WAN, etc. Since I ask for a ‘free’ version, inherently paid features (stronger encryption methods) could also be built in to help fund further development. I am figuring 128-bit AES, SHA, MD5 etc be free vs. the stronger 256/1024/2048 bit methods. Diffiehellman group 2 at least and higher can be a paid service. Also, i’m not reffering to a VPN server run by comodo (akin to Hiamachi) although that too could be another paid service of larger customers who don’t wish to administer the VPN server themselves (again a way to recoup R&D costs). But a standalone VPN server/client install so ppl can feel a little better when sending/receiving data from a fixed source to another.