MidiKeys 1.6b3 (by Chris Reed)
MidiKeys shows a little keyboard on screen, and you can use the computer keyboard to play MIDI notes.

SynthTest 1.2.1 (by Chris Reed)
This is a simple application for OS X that allows you to pick a MIDI source, a MusicDevice AudioUnit and an Effect or MusicEffect AudioUnit to play with.

TestVirtualTools 1.0 (by Chris Reed)
This little package contains two tools I use a lot for testing my MIDI apps on OS X.

Logic Preset Converter 1.0 (by Chris Reed)
The Logic Preset Converter is a free utility application for Mac OS X.

FinderSync 1.0.2 (by Chris Reed)
FinderSync keeps track of the windows that are open in the Finder and listens for changes in the filesystem.

MidiKeys 1.6b3 (by Chris Reed)
MidiKeys shows a little keyboard on screen, and you can use the computer keyboard to play MIDI notes.

MIDI Keyboard Lab File Creator 1.0 (by Toby W. Rush)
MIDI Keyboard Lab comes with over 150 exercises that meet a wide variety of needs and can fit with many different curricula.

MIDI Keyboard 1.7 (by Hopkins Multimedia)
MIDI Keyboard allows for MIDI events to be sent to programs such as Finale, Reason, Garage Band, and others that accept MIDI input.

MidiSwing 0.3.1b (by Pascal Naidon)
MidiSwing is a little midi sequencer.

MIDI Data Miner 1a (by Ollie Glass)
MDM uses a neural network to learn correlations between notes and control changes in a MIDI file.

RandomMIDI 1.0 (by Useful Software)
RandomMIDI produces "random" sequences of pitches from notes played on an on-screen piano keyboard image.

MIDI Keyboard Lab 1.0.2 (by Toby W. Rush)
Keyboard skills are vital for any music student, and the ability to apply music theory concepts to the keyboard strengthens students' understanding of those concepts, as well as increased fluency with the piano keyboard.

Midi Grasshopper 5.4 (by Thinking Cap)
Midi Grasshopper is a MIDI sequencing application.

µ MIDI Controller 2.6 (by Music Unfolding)
Use your computer keyboard & mouse or Wacom tablet to create a musical performance!

Control both your software & hardware MIDI devices.

v.m.k 1.6 (by Fredrik Olofsson Musikproduktion)
This application lets you simulate a midi keyboard on your computer keyboard.

SlimServer 6.5.0 (by Slim Devices, Inc.)
Slim Devices introduces SlimServer 6.

NoteAbilityPro 2.319 (by Keith Hamel)
NoteAbility Pro is a professional music notation package for the Macintosh OS-X operating system.

netTunes 2.3.1 (by Shirt Pocket)
netTunes lets you control iTunes running on one Macintosh from another, using iTunes' native interface.

v.m.k 1.6 (by Fredrik Olofsson Musikproduktion)
This application lets you simulate a midi keyboard on your computer keyboard.

Audio Hijack 2.2.5 (by Rogue Amoeba)
Audio Hijack gives all your audio that extra bit of sweetness.