Rdist:

  Rdist is a very old tool, but unlike other tools that have withstood
  the test of time, it is neither perfect nor very modular.  Rdist is
  used to replicate directories across hosts.  The main use of rdist
  is to run it on a "distfile" --- a script in the language of rdist.
  An example distfile is:

    HOSTS = ( host1.domain
              host2.domain
              ... # a bunch more hosts
              hostN.domain )

    DIR   = /rdist/iX86-Linux-2.2

    ${DIR} -> ${HOSTS}
      install -oremove,compare /;
      except ${DIR}/tmp;
      except ${DIR}/etc/passwd;
      ... # a bunch more files that should be different
      except ${DIR}/etc/shadow;

  This distfile identifies a list of hosts (host1 - hostN), and a
  local directory (/rdist/iX86-Linux-2.2).  It then tells rdist to
  "push" the contents of that directory onto the root directory ("/")
  of the list of hosts.  It also tells it remove any extraneous files
  it should find on the remote machines, and to use binary comparison
  to decide whether or not to update a file on the remote host (normally
  it just looks at the last modification time of the file).  Then, there
  is a list of files not to update on the remote machine.

  A distfile like the above could be used to replicate a site's standard
  software installation on a list of remote machines.  One of the strengths
  or rdist is that it can be performed in parallel --- rdist can open
  connections to more than one machine at a time when "installing"
  software.

  A discussion of rdist could go on for a very long time.  Please read
  the manual page for it.  Among the more interesting things that it can
  do are:

    * When it updates a file, it can run a command
    * Compare the local and remote owner using UID/GID or names
    * Omit a list of files by regular expression, instead of an explicit
      listing of them