Despite living in the age of multicore processors, GUI everything and mountains of ram, I continually find myself more productive with a terminal open. Especially when that terminal is running GNU Screen. About GNU Screen GNU Screen is a free terminal multiplexer developed by the GNU Project. It allows a user to access multiple separate terminal sessions inside a single terminal window or remote terminal session. It is useful for dealing with multiple programs from the command line, and for separating programs from the shell that started the program.