Both correct, adding some concrete dates and names for the technologies: FreeBSD Jails were added in FreeBSD 4 which was released in 2000 Docker (on Linux) is

Both correct, adding some concrete dates and names for the technologies: FreeBSD Jails were added in FreeBSD 4 which was released in 2000 Docker (on Linux) is based on Linux CGroups which were added in 2007 Initial release of docker in March 2013 Initial support for Docker based on jails added to FreeBSD in July 2015