overmind

https://github.com/DarthSim/overmind

Overmind is a process manager for Procfile-based applications and tmux. With Overmind, you can easily run several processes from your Procfile in a single terminal.

• Overmind starts processes in a tmux session, so you can easily connect to any process and gain control over it;
• Overmind can restart a single process on the fly — you don't need to restart the whole stack;
• Overmind allows a specified process to die without interrupting all of the other ones;
• Overmind can restart a specified processes automatically when they die;

If a lot of those features seem like overkill for you, especially the tmux integration, you should take a look at Overmind's little sister — Hivemind!

https://github.com/DarthSim/hivemind

I might want to use one of these for the running the build watcher + http server in observable-plot-template

written in go