screen

screen is a program that lets you run detached processes on unix.

e.g. log into a VPS, start a server, then safely exit the connection while leaving the server running.

how to

$ screen, then run the process (e.g. $ node server.js)
click Ctrl+A+D to detach the session
$ screen -ls to list running sessions along with their id's
$ screen -r [session id] to get back to a session
$ screen -X -S [session id] quit to quit a session