Debian 6.0 (Squeeze): dependency-based boot ordering

The release from February 6, 2011 moved the default ordering of boot scripts away from fixed two-digit numbers in /etc/rcS.d toward dependency-based sequencing through insserv. A script declared what it needed and what depended on it, instead of the order living in a hand-picked filename prefix.

The same release carried, as a technology preview, a port to the FreeBSD kernel (kfreebsd-i386, kfreebsd-amd64) – the same Debian userland running on a kernel other than Linux. Systemd only became Debian's default two releases later (Debian 8 Jessie); Squeeze shows what init looked like before it.