Dan J Bernstein’s (djb) daemontools is a set of programs to help you manage unix services. It provides a flexible, secure and convenient way of starting, stopping and sending signals to background processes. Combined with his ucspi-tcp tools, it can be used as an awesome replacement to inetd (it’s most often used in this way to run qmail, a secure and high-performance mta). It can be fiddly to set up and has a bit of a steep learning curve but I already use daemontools for various other stuff, so it was just natural for me to use it for Ruby on Rails deployment.