Hi, As you may know there exists a cross-platform graphics library called SDL. It is mainly used for games, but it is excellent for normal app's also. Some time ago I wrote a GUI toolkit on top of SDL, called SDL-widgets. It is far from complete, because I focussed on 2 example audio applications, that might also be of interest for visitors of this newsgroup. The first example app is called make-waves. It can: - draw waveforms to the screen, modulate them by each other, you can listen to the result, - draw a physical model of a string or a spring that you can listen to and animate with the mouse, - draw and edit the harmonic spectrum of a sound, - display the frequency curve of digital filters, that you also can plug in yourself. The 2nd example app, wav2spectrum, can read a wave file and perform FFT analysis on it. You can scroll through the cached waveform chunks and FFT spectra easily. I tried to document the toolkit and the examples fairly well, so maybe they have some use for others as well. You can get it from: http://members.chello.nl/w.boeke/SDL-widgets/index.html Kind regards, Wouter Boeke