eurephia is an authentication and access control plug-in for OpenVPN. It improves authentication by adding user/password auth in addition to certificates. Access control is managed via iptables on Linux servers. See web page for more info
SSPE: Simple Security Policy Editor is a simple distributed firewall with an central ascii administration. It uses two plain manually edited ascii-files and some other, static files for each of the target-machines to generate iptables.