One feature I really liked in Solaris 10 was SMF. It provides a framework using services manifests on the system to automatically respawn services should they die off. It handles dependencies, restarts, and a single unified command set to configure the system using svcs, svccfg, and svcadm.
Linux looks like they’ve started to integrate some of these features with a modified Init daemon that not only restarts defined services, but improves boot time. I’m going to be checking Initng out and will post with some further findings.