Well for example if you have a bunch of web servers and you are looking for server errors and you do # tail -f access|grep \ 500\ on all the instances. You

Well for example if you have a bunch of web servers and you are looking for server errors and you do # tail -f access|grep \ 500\ on all the instances. You can then do a regex match on 500 in the app and it will sort the terminal windows that have the most matches to the top. That way you can determine what instances are failing. I don't think parallel-ssh, cssh, tmux do that. and it's web-based too.. Which just makes it different, not better!