Upstart 1.6 able to boot without initramfs
Version 1.6 of Upstart now records state information, enabling it to continue to manage previously launched background services after being restarted. "Stateful re exec" is useful for updates and restarting the init system on the fly. Previously the init daemon, which was developed within the Ubuntu ecosystem, would lose information about previously launched services when restarted. The 1.6 release is also able to boot without using initramfs and the developers have improved the documentation and error handling.
Canonical and the Ubuntu developers are likely to deploy Upstart 1.6 or a later version in next year's version 13.04 "Raring Ringtail". Google's ChromeOS also uses Upstart. Fedora, openSUSE, Mageia and some other distributions currently use systemd (an alternative to sysvinit and Upstart) by default. Red Hat Enterprise Linux 7 (RHEL7), due out next year, will also use systemd – the current RHEL6 uses Upstart.