Daniel J. Bernstein's daemontools package, described by him as "a collection of tools for managing UNIX services", is the pioneer of what some people call today process supervision suites, i.e. packages that provide tools for performing process supervision  . There are no further releases of daemontools after 0.76, but other software packages have been inspired by its design principles, notably runit, s6, perp, nosh, and an enhanced succesor, daemontools-encore .
USE flags for sys-process/daemontools Collection of tools for managing UNIX services
emerge --ask sys-process/daemontools
- /service - Location of the scan directory when using OpenRC or svscanboot.
See here for details.
emerge --ask --depclean sys-process/daemontools
The same extra steps after removing daemontools-encore apply here.
- runit — a daemontools-inspired process supervision suite that also provides a program suitable for running as process 1
- OpenRC — a dependency-based init system that maintains compatibility with the system provided init program
- systemd — a modern SysV-style init and rc replacement for Linux systems.
- https://cr.yp.to/daemontools/install.html - A very short guide on how to install daemontools.
- D. J. Bernstein, daemontools FAQ, which includes one about the benefits of process supervision. Retrieved on April 23rd, 2017.
- Gerrit Pape, runit benefits, which includes a short description of process supervision in general. Retrieved on April 23rd, 2017.
- Laurent Bercot, s6 overview, which contains an introduction to process supervision. Retrieved on April 23rd, 2017.
- Jonathan de Boyne Pollard, The daemontools family. Retrieved on May 16th, 2017.