systemd is a boot sequencer and service manager for Linux systems, with optional facilities for network management, logging, session control and cryptography. It is used by a majority of desktop Linux users, as its adaptiveness to changing hotplug hardware, network connectivity and its support for sandboxing makes it attractive for workstation/laptop use.
systemd is a system and service manager for Linux, compatible with SysV and LSB init scripts. systemd provides aggressive parallelization capabilities, uses socket and D-Bus activation for starting services, offers on-demand starting of daemons, keeps track of processes using Linux cgroups, supports snapshotting and restoring of the system state, maintains mount and automount points and implements an elaborate transactional dependency-based service control logic. It can work as a drop-in replacement for sysVinit.
More here at http://0pointer.de/blog/projects/systemd.html#faqs
