Don't forget daemontools.
Daemontools is nice because it works fine as a init.d replacement, and you can just run the individual programs when appropriate. I use it to start emacs, offlineimap, etc., when I log in for the first time.
daph:/etc/service# svstat *
apache: up (pid 20546) 7315393 seconds
dndr: up (pid 32629) 3757174 seconds
getmail: up (pid 31632) 4487516 seconds
momo: up (pid 22310) 16934 seconds
mush: up (pid 10708) 222304 seconds
p9: down 7991823 seconds, normally up
u9fs: up (pid 13547) 1968001 seconds
win2k: up (pid 3291) 8180332 seconds