.sh

[atl2ptown]

what extension is this, and what command do i run to extract it?

[Piston]

It is a shell script, so to run it you can chmod 777 <i>filename.sh</i> to make it executable and then just type ./<i>filename.sh</i> at the prompt from the directory it's in, or you should be able to type sh <i>filename.sh</i> at the prompt if you're in the correct directory to run it.