I am looking for a VPN software that will run on Windows (Mac/Linux would be a bonus), that are similar to other packages such as Hamachi that will automatically work behind a NAT or Firewall. Also, it needs to run as a service, so the user does not have to be logged in. I can run my own server if need be.
Hamachi, Remobo and GBridge are great, but they are limited to the number of machines you are allowed for free, or do not allow running as a background service.
I see there are some open source possibilities - OpenVPN, n2n, but I am not sure if they will do the windows/service/nat-firewall.
LeafNetworks looks like it might do the trick, I am going to try it out, but I am just concerned that it appears free for now, but then at some point it may become pay.