GtkGEP turns your computer into a realtime effects processor. You can plug
your guitar into the computer and play with cool distortion effects, for
example. It has a modular plugin structure, with standard plugins including
distortion, overdrive, delay, reverb, equalizers, and a flanger. It works
in 16-bit resolution, in mono mode, and with frequencies from 11khz to
44khz. The sound quality is very good.