xdemorse is a GTK+ based Morse code signal decoder. It has an 
integer-arithmetic FFT-derived "waterfall" display of the incoming 
audio signal's spectrum, as well as a 'scope-like display of the 
audio detector's output and status of the mark/space discriminator 
("slicer"). xdemorse also has CAT for the FT847 and FT857 and 
this can be used to net the receiver's frequency to the incoming 
signal, by clicking near its trace in the waterfall display.