Major: Supporting Linux, OS X and Windows (not CygWin)! Avoid mixed line from multiple processes without loss of performance, e.g. the first half of a line is from one process and the last half of the line is from another process. (--line-buffer in GNU parallel) Timeout (-t). (--timeout in GNU parallel) Retry (-r). (--retry-failed --joblog in GNU parallel) Safe exit after capturing Ctrl-C (not per