parallel

GNU.

Basic usage

Run echo 100 times in parallel:

seq 100 | parallel echo '{}'

halt

Determines what happens on failure:

seq 100 | parallel --halt=0 false
echo $?

0: default. Don't halt on failure. Exit status is the number of failures.
1: don't start new processes on failure. Exit status is the last failure.
2: kill everyone else on failure.