Apologies for a noob question, but I'd appreciate any help!

I'm trying to download a web applet for offline use. The applet in question is here: http://www.quantum-twist.com/index2.html

I've downloaded the jar it uses (http://www.quantum-twist.com/MetronomeApplet.jar) but don't know how to run it locally, or whether I can. I'm on a Mac running Snow Leopard.

My two questions are: can this be run locally (i.e. does it need to communicate server-side at all) and, if so, how do I run it on a Mac?

EDIT: First thing I tried was java -jar MetronomeApplet.jar in Terminal, nothing happens. Terminal waits a split second, then gives me another command line.

I also tried using appletviewer (from Terminal), but that just opens an item in the Dock for a couple of seconds before disappearing.