Both are pretty similar. Strangely, I’m sitting at a Ubuntu 8.10 box and see no evidence of Upstart on the system… maybe I haven’t had enough coffee, or maybe this particular install is still just using straight sysvinit for some reason. In past experience — about a year ago — Upstart seemed reasonable but for the fact that it retains backwards compatibility with sysv scripts [so at that time, Ubuntu was shipping it with essentially no native configuration] but it wasn’t behaving exactly like sysvinit, so it could become a day at the race conditions when it tried to spawn everything at once.

Personally, I don’t mind daemontools conceptually, but I find I’m always getting into whack-a-mole situations when making live configuration changes and doing stupid things like killing svscan instead of supervise. If svscan were doing anything other than running djbware, maybe I’d learn not to do that.