PG Music
Makers of Band-in-a-Box, PowerTracks, Modern Jazz Pianist, Latin Pianist, others for Mac and IBM.
http://www.pgmusic.com/

Evolution
Music software and hardware for the PC. Demos available.
http://www.evolution.co.uk/

Hit Squad
Many free music software downloads. Many guitar links plus tab, online discussion forums.
http://www.hitsquad.com/

Steinberg
Includes Cubase, Wavelab, Nuendo, plug-ins, and synthesizers. Win, Mac, and Silicon Graphics.
http://www.steinberg.net/

Cakewalk
Featuring programs like Sonar and Project5 and other synths and effects.
http://www.cakewalk.com/

Harmony Central
Covers product announcements and industry news, reviews and links.
http://www.harmony-central.com/

FlexiMusic
Programs to generate, compose, edit, compress and DJ. Downloads available. Windows.
http://www.fleximusic.com/

Singing Electrons, Inc.
Audio products and utilities, audio software development services.
http://www.singingelectrons.com/

Native Instruments
Several synths, samplers, effects and sound libraries. Features, audio samples, demos, support area.
http://www.native-instruments.com

Bludgeonsoft
Small and unusual experimental audio software, usable for live performances.
http://www.wizardmaster.com/bludgeonsoft/audio.html

GMEDIA Music
Developing virtual instruments, effects and utilities. Products description, technical support, distribution and purchasing information.
http://www.gmediamusic.com/

Phonature Visualization Technology
For PocketPC, Palm, and mobile phones. Includes PhonTuner, Visual Guitar tuner, HandDee-SA spectrum analyser.
http://www.phonature.com

InTime
Interactive tempo and beat-tracking program from Circular Logic. For practice and live performances. MIDI save option.
http://www.circular-logic.com

Deepsound
JavaScript sample calculators, time-stretch, pitch-shifting, sample length, delays, sampling rates, and durations.
http://deepsound.net/calculation.html

iPodder
iPodder is small program that runs on your computer. Its only purpose is to download audio files, usually mp3s, directly to an mp3 device.
http://ipodder.sourceforge.net/

Voicealizer
Simple interface to enables users to place voice recordings onto any web site or weblog using the phone or a microphone. Product features, online demonstration, and purchase.
http://www.voicealizer.com/