Gzip several files at once, using all cores:
parallel gzip ::: file1 file2 file3
Read arguments from stdin, run 4 jobs at once:
ls *.txt | parallel -j4 gzip
Convert JPG images to PNG using replacement strings:
parallel convert {} {.}.png ::: *.jpg
Parallel xargs, cram as many args as possible onto one command:
args | parallel -X command
Break stdin into 1M blocks, feed each block to stdin of new command:
cat big_file.txt | parallel --pipe --block 1M command
Run on multiple machines via SSH:
parallel -S machine1,machine2 command ::: arg1 arg2