Let's Talk Musical Software

I was hanging around on Sourceforge the other night and did a little searching for music software.  The following is not an exhaustive list but they are all open source, free, and frequently multi-platform.  Download and let your musical freak flag fly!

INSTRUMENTS

open source Boss pedalboard controller: Win/BSD/Mac/linux

guitar tuner java applet: Win/Mac/linux

Linux and the Fender Mustang modeling amp
[no .NET or Silverlight required]

guitar effects: linux

guitar effects: Win/linux

Line6 PocketPOD editor: Win/Mac/linux

guitar effects DAW plugins: Win/BSD/Mac/linux

plugin pack for LADSPA, DSSI, LV2 and JACK

guitar amplifier: linux (JACK)

advanced drum machine: Win/BSD/Mac/linux

java drum machine: Win/Mac/linux

java organ builder: Win/Mac/linux

virtual midi piano keyboard: Win/Mac/linux

sound and music synthesis system: Win/BSD/Mac/linux

multitrack guitar tablature editor and player: Win/Mac/linux

music tabulature editor: BSD/linux

RECORDING

free reverb: VST

MIDI sequencer+notation editor: Win/linux

audio/midi multitracker: linux

simple yet powerful multitrack studio: Win/BSD/linux

complete music workstation: Win/Mac/linux

full featured, audio capable MIDI sequencer: Win/BSD/linux

complete a/v production environment: BSD/linux

fast multitrack recorder/editor: Win/BSD/Mac/linux

notation and composition: Win/BSD/Mac/linux

full studio: Win/BSD/linux