Who needs sliced bread?
Once, long ago, I poked at daemontools -- and saw that it was good, but the licensing was quite unworkable.
runit, while similar to daemontools, makes the occasional well-thought-out improvement here and there -- and unlike at least one other daemontools-inspired toolkit, is robust, stable and well-documented. Bravo!
FWIW, I maintain a runit RPM for my employer's use, and would be glad to share this should anyone be interested.
An open, cross-platform journaling program.
A scientific plotting package.