Just installed the TK PDC server and loving it. I installed it to provide PDC services to my SoftEther VPN server install, and noticed you have the Open VPN server appliance.

I would love to see a linux SoftEther appliance, as softether has a Linux version for Debian 7! I find it faster with configurations for many different VPN connections including OpenVPN, Azure, IPsec/L2TP, PPTP, MS-SSTP. It also includes  L2/3 Bridging, and other helpful bits like AD/Radius Login, as well as plain password.

I think it would be a very useful addition to TK.

Softether: https://www.softether.org/