This tutorial shows off much of GNU parallel‘s functionality. The tutorial is meant to learn the options in GNU parallel. The tutorial is not to show realistic examples from the real world.

https://www.gnu.org/software/parallel/parallel_tutorial.html#GNU-Parallel-Tutorial

Shell tool for executing jobs in parallel

http://linuxsoft.cern.ch/cern/centos/7/cern/x86_64/repoview/parallel.html
http://linuxsoft.cern.ch/cern/centos/7/cern/x86_64/Packages/parallel-20150522-1.el7.cern.noarch.rpm