Edit: I started questioning my memory of this, so I poked around some. Poul-Henning Kamp did the initial work in April, 1999, here is the commit:
https://svnweb.freebsd.org/base?view=revision&revision=46155
More details from him about it:
http://phk.freebsd.dk/sagas/jails/
Basically saying that 'containers on Linux' are 'made at Google' is not true.