Mixman

DJ mix/remix software for creating music live or in session.
http://www.mixman.com/

PG Music

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

Steinberg

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

SintesiDelSuono

Shared sound synthesis development, uses the Web to do sonic collaboration among musicians.
http://www.publinet.it/FreeWeb/sintesidelsuono/

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/

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. It's only purpose is to download audio files, usually mp3s, directly to an mp3 device.
http://ipodder.sourceforge.net/

iPodderX

Podcast client and newsreader for Mac OS X.
http://ipodderx.com/