интерфейс D-Bus системы systemd (The D-Bus interface of systemd)
Примечание (Note)
1. polkit
https://www.freedesktop.org/software/polkit/docs/latest/
2. New Control Group Interface
http://www.freedesktop.org/wiki/Software/systemd/ControlGroupInterface/
3. Booting Without /usr is Broken
http://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken
4. the usual interface versioning guidelines
http://0pointer.de/blog/projects/versioning-dbus.html
