Libreswan is described as 'Ibreswan is a free software implementation of the most widely supported and standarized VPN protocol based on ("IPsec") and the Internet Key Exchange ("IKE"). These standards are produced and maintained by the Internet Engineering Task Force' and is a VPN service in the security & privacy category. There are three alternatives to Libreswan for Linux, Android, BSD and Mac. The best Libreswan alternative is strongSwan, which is both free and Open Source. Other great apps like Libreswan are IPsec-Tools and Openswan.
strongSwan is an Open Source IPsec-based VPN solution for Linux and other UNIX based operating systems implementing both the IKEv1 and IKEv2 key exchange protocols.
strongSwan is the most popular Android, Mac & Linux alternative to Libreswan.
strongSwan is the most popular Open Source & free alternative to Libreswan.
IPsec-Tools is a port of KAME's IPsec utilities to the Linux-2.6 IPsec implementation. It supports NetBSD and FreeBSD as well.
Openswan is an IPsec implementation for Linux. It has support for most of the extensions (RFC + IETF drafts) related to IPsec, including IKEv2, X.509 Digital Certificates, NAT Traversal, and many others.
