- [GVPE](http://software.schmorp.de/pkg/gvpe.html)
- [l2tpd](http://sourceforge.net/projects/l2tpd)
- [Nest](http://www.targeted.org/nest/)
-- [OpenS/WAN](http://www.openswan.org/)
+- [OpenS/WAN](https://www.openswan.org/projects/openswan/)
- [OpenVPN](http://openvpn.net/)
- [Poptop](http://poptop.sourceforge.net/)
- [QuickTun](http://wiki.qontrol.nl/QuickTun)