[problems]

What about runit?

Unlike all of the above, runit isn't complicated. You write a tiny, often one-line script and it executes, if it exits, it waits a reasonable amount of time and restarts it.

Not only is it not complicated, but it runs beautifully on top of an existing init system. So now wherever I go I have one tiny script that will start my python based web services and similar. I run the same basic script on freebsd rc, ubuntu upstart and arch systemd boxes.