GuitarINUX!

Guitarix is a simple Linux Rock Guitar Amplifier for JACK Audio Connection Kit with one input and two outputs. Designed to get nice thrash/metal/rock/blues guitar sounds. There are controls for bass, middle, treble, gain (in/out), compressor, preamp, tube's, drive, overdrive, oversample, anti-aliase, fuzz, balance, distortion, freeverb, impulse response, vibrato, chorus, delay, crybaby(wah), ampselector, tonestack, and echo. For 'pressure' in the sound you can use the feedback and feedforward sliders. »

Rakarrack is a richly featured multi-effects processor emulating a guitar effects pedalboard. Effects include compressor, expander, noise gate, graphic equalizer, parametric equalizer, exciter, shuffle, convolotron, valve, flanger, dual flange, chorus, musicaldelay, arpie, echo with reverse playback, musical delay, reverb, digital phaser, analogic phaser, synthfilter, varyband, ring, wah-wah, alien-wah, mutromojo, harmonizer, looper and four flexible distortion modules including sub-octave modulation and dirty octave up. Most of the effects engine is built from modules found in the excellent software synthesizer ZynAddSubFX. Presets and user interface are optimized for guitar, but Rakarrack processes signals in stereo while it does not apply internal band-limiting filtering, and thus is well suited to all musical instruments and vocals. Rakarrack is designed for Linux distributions with Jack Audio Connection Kit. »

ExEf (Extreme Effect) is an extremely powerful and flexible Real Time effect engine running on a PC under LINUX. It is designed to work with guitars, microphones and other instruments. It can run both in X Window System and command line.

GNUitar is guitar effects software that allows you to use your PC as guitar processor. It includes the following effects: wah-wah, sustain, distortion, reverberator, echo, delay, tremolo, vibrato, and chorus/flanger.