bin = binary. i.e. it is exectuable, so you should be able to double click on it or run it from a command line "./limewire_is_slow_and_rubbish.bin". if that does not work set is executable "chmod +x limewire_smells.bin"
btw. i don't like limewire, it gives newbies such horrible horribile java problems. just use a decent natve client instead like http://gtk-gnutella.sf.net
i presume you only after limewire as you may have used it in windows?