What is the difference between .command, .tool, and .sh file extensions?
.command - (Terminal shell script) Specifically associates a shell script with Terminal. Sometimes referred to as a "Terminal File."
.tool - (Terminal shell script) Same as the ".command" file extension.
.sh - (Shell Script) A basic shell script that is associated with Xcode 4.1.


Programmatically, I'm sure the difference between the first two (.command vs. .tool) are subtle, while the third is essentially a simple, default shell script. And does in fact associate with Xcode 4.1.