Here is the corrected table: 4.10: System V (in 2004), first release, adopted from Debian 6.10: Upstart (in 2006), see http://upstart.ubuntu.com/index.html ht

Here is the corrected table: 4.10: System V (in 2004), first release, adopted from Debian 6.10: Upstart (in 2006), see http://upstart.ubuntu.com/index.html http://upstart.ubuntu.com/index.html 16.04: systemd (in 2016) and it was gradual. This is part of the natural evolution of software. There are new requirements and new software is needed to implement them.