Debian GNU/kFreeBSD is an operating system released by the Debian project. It uses the kernel of FreeBSD combined with a GNU based userland. The majority of software in Debian GNU/kFreeBSD is built from the same sources as Debian GNU/Linux. The k in kFreeBSD is an abbreviation for kernel of, which refers to the fact that only the kernel of FreeBSD operating system is used. The Debian project maintains two ports based on the FreeBSD kernel, "kfreebsd-i386" and "kfreebsd-amd64".
Debian developers have cited OSS, pf, jails, NDIS, ZFS and central management of code licenses as reasons for being interested in the FreeBSD kernel.
Debian GNU/kFreeBSD was included in Debian 6.0 (Squeeze) as a "technology preview", and in Debian 7.0 (Wheezy) as an official port.
The Debian popcon registers the usage of a subset of Debian users. As of February 2014, popcon registered 130 kFreeBSD, compared to 32 HURD users, and 165,821 Linux users. So according to popcon, there are 1,276 times as many Linux users as there are kFreeBSD users.