- some form of unittests (shell scripts? sub-process?)
    eg, https://github.com/uutils/coreutils/tree/master/tests
- better error handling (no unwraps)
- install command including manpages
- TCP backlog argument
- --kill-children-on-exit
- --seconds N
- argument to create a pid file

nice to have:
- refactor code into multiple files
- design docs/notes
- more examples: rust, golang, C, ruby, js/node
- exponential backoffs
- debian packaging
- shell: timeouts on requests
- explicit drop()s on timer guards in some places
- more formal top-level state machine?
- systemd, upstart, and sysV template init files