FreeBSD jails are like a really mature, full-featured version of LXC as opposed to "just a chroot". In addition to being chroot that provides real filesystem isolation without many of the security issues of a Linux chroot, it also has CPU and memory limits, disk quotas, network isolation, root privilege isolation, all the magical ZFS goodness (provided you're running the jail on ZFS). It's really, really nice.

This is a pretty good overview: https://en.wikipedia.org/wiki/Operating-system-level_virtual...