Libreswan
Libreswan is a fork of the Openswan IPsec VPN implementation.
Libreswan is created by almost all of the Openswan developers after a lawsuit about the ownership of the Openswan name was filed against Paul Wouters, the release manager of Openswan, in December 2012. The lawsuit was later settled out of court. The Libreswan project has an active community of developers and contributors with regular releases. They can be found on the #swan channel on the Freenode IRC service.
Libreswan supports most of the common type of IPsec configurations people use including configuration like host to host VPN, subnet to subnet VPN.
