FreeBSD Jails is described as 'The FreeBSD jail mechanism is an implementation of operating system-level virtualization that allows system administrators to partition a FreeBSD-based computer system into several independent mini-systems called jails' and is a Virtualization tool in the network & admin category. There are seven alternatives to FreeBSD Jails for a variety of platforms, including Linux, Mac, Windows, Self-Hosted and VMware Workstation Pro apps. The best FreeBSD Jails alternative is Docker, which is both free and Open Source. Other great apps like FreeBSD Jails are Vagrant, containerd, rkt and Singularity.