guitarix is a virtual guitar amplifier for Linux running with jack (Jack Audio Connection Kit). It is free as in speech and free as in beer. Its free sourcecode allows to build it for other UNIX-like systems also, namely for BSD and for MacOSX.
It takes the signal from your guitar as any real amp would do: as a mono-signal from your sound card. Your tone is processed by a main amp and a rack-section. Both can be routed separately and deliver a processed stereo-signal via Jack. You may fill the rack with effects from more than 25 built-in modules spanning from a simple noise-gate to brain-slashing modulation-fx like flanger, phaser or auto-wah. Your signal is processed with minimum latency. On any properly set-up Linux-system you do not need to wait for more than 10 milli-seconds for your playing to be delivered, processed by guitarix.
guitarix offers the range of sounds you would expect from a full-featured universal guitar-amp. You can get crisp clean-sounds, nice overdrive, fat distortion and a diversity of crazy sounds never heard before.
guitarix on YouTube
...and even more out there
guitarix is a native Jack-application. Thus you can combine it with any other Jack-aware software installed to your Linux-box.
If You want to use more FX than we provide built-in guitarix, you can also select plug-ins from the large list of LADSPA plug-ins. Or just connect the Jack-out of guitarix with the Jack-in of Rackarrack or any other Jack-aware FX-host.
Though we design guitarix with guitar-signals in mind there is nothing wrong with connecting a synth or any other sound-generator with it.