Add an ampersand to the end of the line, e.g.:
... this pushes the job into the background (it runs in a sub-shell). If you have already launched the program, hit Ctrl-Z
to stop it temporarily, then type bg
and hit return to restart it in the background.
In each case, you will be given a job id and its process number. To get a summary of background tasks in a particular shell, run jobs
. You can address each job by its number preceded by a %, e.g. kill %2
to terminate the second background job.