Shmux is program for executing the same command on many hosts in parallel. For
each target, a child process is spawned by shmux, and a shell on the target
obtained one of the supported methods: rsh, ssh, or sh. The output produced by
the children is received by shmux and either (optionally) output in turn to the
user using an easy to read format, or written to files for later processing
making it well suited for use in scripts.

WWW: http://web.taranis.org/shmux/